Ruff Ruffman (voiced by Jim Conroy) whose full name is Master Ruffilicious Ruffykins is the host of the show. He does not like cats, or at least thinks that dogs are superior to them in most ways. He has a crush on Charlene. Ruff grouses about his contract to produce a reality TV program, and the stresses of running one. He loves all food, American-Chinese take-out in particular. His physical appearance features "eyebrows that hover mysteriously above his head". Ruff has many relatives and ancestors, all with a physical appearance similar to his own, and he has five brothers and sisters besides Scruff and Roxy. According to the episode Ruff Bounces Back, Ruff is a mutt and is proud of it.
Blossom, whose full name is Princess Blossom Pepperdoodle Von Yum Yum, is a black cat who never speaks and was Ruff's intern for Season 2. She is usually called "Blossom". Quite serious, she is often seen taking notes on her laptop. She was promoted to supervisor in Season 3. Ruff did not enjoy Blossom's company at first, but in the later seasons forms a close bond with her. Despite all of the hijinks that Ruff puts her through, she continues to be loyal to Ruff and the show, particularly when she decided to 'work' for Harriet Hackensack so she could find out the reason for her misocyny (hatred for dogs). In "Don't like Fencing? Try Fencing!", Blossom is shown watching Design Squad (and also shows that she is a fan of Nate from the show).
Grandma Ruffman, also voiced by Conroy, is Ruff Ruffman's grandmother who appeared in nineteen episodes: Grandma Ruffman's Recipe for Success, The Small Fork Is For Dessert (Unless You're a Dolphin), Tape Loops and Loop-the-Loops, There's Food Safety and Then There's Food Safety, Socket to Me, The People vs. Grandma Ruffman, the FETCH! with Scruff Ruffman Finale, Season Four is Cancelled, Is It a Bird? Is It a Plane? It's... Ruffmanman!, Ruff Needs His Herring Checked, Gearing Up for Getting Ruff's Goat, How to Really Train Your Dog, Ruff Fetches The Fetchers, Game Show Isle, How Much Frosting Can You Bear, That Sculpture Isn't Yours, It's Mime, Go Belugas Go!, Long Glen Silver and the Pursuit of the Golden Fetchie! and The FETCH! Finale.
Henry is Ruff's boss, never seen but occasionally calling Ruff on the "Henry Hotline" (except for "Yippee Tie Yie Yay, Get along, Little Doggies"). Henry provides Ruff with the show's budget and oversees Ruff's spending. He also sent the intern Blossom, his niece's cat, to learn about producing during Season 2. In Season 3 onward, Henry is mentioned less and less, probably because Blossom is now head of the network. Henry's last "appearance" was in the series finale, where he forced Ruff to make a worthy season finale, despite the fate of the world being on the line. It is possible that "Henry" is a reference to Henry Becton, Jr., the former President of WGBH, and currently Vice Chair of the WGBH Board of Trustees.
Murray is one of Ruff's cousins. He runs the behind-the-scenes technical work, and is constantly blamed for minor problems regarding the show. Unlike the other animated animals, Murray is portrayed by a real basset hound, and sometimes appears in the kids' challenges. He stopped appearing at the start of Season 4.
Chet, a brown mouse, is Ruff's intern, first appearing in Season 3 to replace Blossom when she is promoted. He also does not speak and he does not seem to have any eyes or limbs (this was mentioned by Ruff in some episodes) and resembles a computer mouse. He is capable of doing feats that one would normally consider impossible, such as completing an obstacle course in seconds and building a jet engine that runs solely on milkshakes. Like Blossom, Ruff did not like Chet at first, but was friends with him eventually.
Tank replaced Murray in Season Four. He is a real bulldog who wears a FETCH! shirt and earmuffs. Though it does not seem like it at first, Tank has proven to be a reliable worker; Ruff says that he has Tank because "he's a bruiser" (hard worker), and looks good in a FETCH! shirt". He usually just smiles and pants at the camera, while Ruff replies "Hello? Anyone home in there?".
Charlene Poodle is Ruff's unrequited love interest. She is a poodle who is only seen in a heart-shaped picture that Ruff periodically pulls out, as well as a newspaper in Season 4's first episode. She has a mother named Knell with a silent "k" which Ruff mistook for Nell.
Scruff Ruffman is Ruff's identical (but evil) twin brother. He steals artwork in the episode Scruff Ruffman At Large!, leading to one of the episode's challenges. He also stole the Grand Prize in Season 2, which was recovered by Blossom, and is an expert trapeze artist. He appears twice in Season 3, first in The Ol' Switcheroo, where he is in Ruff's basement, and then in the Finale, where he becomes a host along with Ruff. At the end of the episode, Scruff ends up stealing all of Ruff's stuff and selling it on the internet so that he could pay for luge lessons to remove a curse from the Ruffman ancestry. He and Ruff team up to finish the World Luge Championship which—despite ending in last place—made them famous for being the first all-canine luge team (helping lift the 1000 year sled curse on the Ruffmans and helped Harriet Hackensack like dogs once more). Despite that fame, he was soon sent back to Poodle Island Prison, sending a video to Ruff requesting to send him the Helmet of Victory in "How to Really Train your Dog." In Season 5, he only appeared in "This Sculpture isn't yours, it's mime!", which shows he was released from prison, and is staying with Grandma Ruffman.
Ruffael Ruffmanowitz is Ruff's great-great-great-great-great-great grandfather. He was only seen in photographs, first in a Season 1 episode, The Mystery of the Missing Thing in the Haunted Castle, and in the season 5 episode " 'Eureka' is not a Brand of Dog Food". Was the dog of inventor John Hays Hammond, Jr.. He looks like Ruff, except with hair and a mustache like Albert Einstein's . He invented the FETCH 100, a primitive version of the FETCH 3000, which unfortunately calculated that 3 plus 3 is 24. The FETCH 100 is a possible reference to Colossus, the first "true" computer ever made. He made his first "speaking appearance" in a Season 5 episode, as automated picture frames with apparent recordings in them that are activated through buttons.
Ruff McRuffmantosh is Ruff's great-uncle who has a beard and speaks with an exaggerated Scottish accent. He has appeared in the episodes The Mystery of DogTopia and Catlantis, The DogVinci Code, Arrgh - All Me Eggs Are Cracked!, Season Four is Cancelled, How To Really Train Your Dog. He is usually worried about the FETCHers going on potentially dangerous missions and is a believer in legends, monsters, and curses. In the episodes, he usually finds clues for treasure-related challenges. His outfit is a powder blue T-shirt with a dark blue traditional kilt. His name is a possible pun on the Macintosh computers. At the end of the second episode of Season 4, Uncle McRuffmantosh is on the hunt for the Helmet of Victory. He knows a lot about different legends (ranging from Dogtopia/Catlantis, Blackmuzzle's treasure, and Dogvinci's sketchbook), but ironically has a memory problem (stated in "How to Train Your Dog").
Spot Spotnik is Ruff's rival. He is tan with brown spots, and is mentioned in Send in the Clowns, when the kids build a water balloon launcher to get back at him, in You Lucky Dog when Ruff challenges him to a race, in How to Get Dogs and Doggerel in Better Shape when he tries to win Charlene's love, and in Just Call Him "Spot" when he tricks Ruff into drawing spots on himself with permanent marker. In Season Four is Canceled a picture of Spot, showing him with a much better physical appearance than Ruff. His name is a possible pun on Sputnik. Also in that same episode, Spot sent Ruff a phony fax that told Ruff he was fired. In Ruff Fetches the Fetchers he auditions for the show, but Ruff decides to not hire him. In The Ol Shell Game he sends Ruff a bunch of turtleneck shirts, telling him that turtles have long necks which they're able to roll up like a hose. Ruff, upset, makes up a show called Who's the Smarty Pants and invites Spot to be on it. But Spot sends Ruff an invitation in return, and Ruff sends Jay in his stead.
Helga von Ruffman is Ruff's cousin, a fashion designer from Germany. She is first shown in the Season 2 episode Take Me Out to the Fashion Show. In that episode, she tells Ruff that if he can get a good enough fashion, she will let him visit her. She, at first, is mad with his choice of clothes, until the end of the episode (when Ruff's outfit is based on the trash he was supposed to throw away). She appears again in "How to really Train Your Dog" in a video, asking Ruff to give her the Helmet of Victory (stating that her birthday was before Grandma Ruffman's and Ruff had to make it up to her). She reappears in Season 5, when she sends Ruff her "Helga Collection" of jewelry for safekeeping while she comes to America to sell it. In a podcast, she invites Ruff to be a fashion model, which on the journey, Ruff had to take a plane to Philadelphia to take a submarine and avoid a giant squid. Then Helga put him in his dress called "The Ruff Ruffman Collection" which was based on the garbage. when she puts on the banana peel shoes Ruff slip into the crowd. When coming back to America, the submarine has to avoid sea monsters and man-eating sharks. In a voice mail she tells him to be a cosmetic chemist to make makeup.
Glen Ruffman (aka Glendalf, Ultra-Glen, Long Glen silver, and The Green Avenger as heard in a voicemail) is Ruff and Scruff's nephew. He wears dental braces and is obsessed with magic and fantasy, and makes his first appearance in the Season 3 episode Dog of the Rings to sends the FETCHers to Wing's Castle portrayed as LARPers (Live Action Role Players). He also briefly appears in the beginning of the Season 3 Finale, changing all of the passwords of the Fetch 3000 so that Scruff can run the show instead of Ruff (however, he says he would not have done it if Scruff had not "promised him the Scepter of Wogganot", which was nothing more than a toilet brush). He briefly appeared again in Season 4's first episode telling his uncle to luge. Due to his braces, it is hard to understand what he's saying (An example being what Ruff heard as "Ring Goblet" was Glen actually saying "Wing Goblet"). In it's a bird? it's a plane? it's...Ruffmanman, Glen adopted a superhero identity after reading comic books and redubbed himself "Ultra-Glen". He also appears in How to Really Train Your Dog, asking Ruff to give him the Helmet of Victory so that he could "no longer be a looger (loser)". In Long Glen Silver and the Pursuit of the Golden Fetchie, he has been playing a pirate-themed video game on the Go Get It! website and calls himself "Long Glen Silver" and makes Ruff dress as his parrot. It is possible that Glen's name is a reference to Glen Berger, the program's head writer.
Gerry Geranium is Grandma Ruffman's pet parrot who Ruff sometimes parrotsits. He is a master at checkers, with his catchphrase being "Squawk! King me, booby!" However, in the season 4 finale, he explains to Ruff that his parents are alive (Ruff mentioned to Blossom that they vanished when he was a pup).
Rüf Rüfman is Ruff's Swedish rock star/environmentalist cousin. He speaks with a Swedish accent and sometimes uses Swedish phrases or sayings. He is seen in Ruff Rocks the (Environmentally Sustainable) House, when he has a concert booked in South Carolina, but he needs a "green" place to stay, so the Fetchers go build him one, while the others are learning how to play rock. In Birds are Handy he tells Ruff that if he can get recordings of birds, he "can dance with han(d)s", which Ruff misunderstands as "dance with Hans Ektershooping", a Swedish pop star.
Bluff Ruffman is another one of Ruff's cousins. He talks in gangster lingo and wears sunglasses and a gold necklace. According to Ruff's voicemail, Bluff likes to play Crazy 8s with his friends. He appeared in When Home is a House of Cards in Season 3. He is seen at the end of "How to Really Train Your Dog", stating that he's selling front row tickets for the family to see the finale (despite Helga mentioning that it was on television, so he could not sell tickets). Also, in the season 5 episode Look What the Dog Dug Up!, he sends Ruff a sandwich shaped like him. Ruff finds what he thinks is a real Egyptian sarcophagus, when he buries it, and clues lead the FETCHers to a "tomb", which contains only an advertisement for Bluff's beef jerky. In a podcast, he is answering to Ruff's secret radio show for Grandma Ruffman's birthday. In a voicemail he tells Ruff to be a statistician to help them with card games. In another he tells Ruff to be a landfill designer so he could hide Skinny's lucky playing cards. In another he tells Ruff to be an art conservator so he could help him with art he had stolen.
Blackmuzzle Ruffman is the most feared canine pirate of the seven seas. He appeared at the end of Arrgh - All Me Eggs Are Cracked! for pledging the show with his own loot. Strangely, he's a ghost but is animated as if he was still alive. He appeared in the middle of Season four is cancelled to attack Ruff's doghouse boat because he was bored and Ruff refused to give him Jerry to replace a frog on his shoulder. He told Ruff that he recently acquired the internet so that he does not have to shout from his ship; in response Ruff told him to visit his website, which he does so, allowing Ruff, Blossom, and Chet to lose him. In a voicemail he tells Ruff to be an oceanographer so he could help him navigate the sea.
Roxy Ruffman is Ruff's sister. She is mentioned in Feeling Sheepish Ruff? where she has Ruff lambsit her sheep.
Mrs. Kate Taylor Ruff's owner. She never appears on the show, but can be heard occasionally calling Ruff to dinner, or in Season 5, telling him to fetch.
Mrs. Harriet Hackensack is the new owner of Ruff's network company which she has recently bought at the start of Season 4. She dislikes Murray for stealing her valuable sled Rosebud.
Fleape Itcherson A flea who sets up residence in Ruff's ear, and speaks in Ruff's ear with a sultry Latin voice in "Ruff Needs His Herring Checked", giving him advice on wooing Charlene. At first, Ruff thought he was the only one who could hear the voice because of his sensitive dog hearing, but when he could still hear the voice after using a noise-cancellation box, he began to think he was losing his mind. In Wolfing Down Some Barbeque, he advises Ruff to make better barbeque. He appears on a game on the website telling Ruff about a freeze dance party hosted by Chet Ruff shows him a clip of The Legend of Ruffman's Gold".
Le Purr first surfaced in "Laser/Candid Camera." As Scruff is Ruff's evil twin, Le Purr is Blossom's evil twin (her real name being DuchessPetuniaCupcake Von Yum Yum). The name is pronounced with a slight roll of the "r"s at the end. Le Purr is a master of disguise (as seen in the photo album Blossom keeps in her desk), loves flowers and disco music, and regularly steals flowers that are being delivered and replaces them with CDs of annoying disco music. Her lair is protected by a disco ball which refracts lasers. Petunia wears pink cat's eye glasses while Blossom wears round lenses.
Gus Ruffman is Ruff's great-great-great-great uncle, a prospector around 1859. Ruff said that he was a pack rat, having stored all of his belongings in his basement. He spoke with a Southern accent. He only appeared in Season 5, when Ruff and the FETCHers sought his hidden treasure, which turned out to be not gold but laundry detergent; he considered the latter to be more valuable than gold because everyone's clothes were always dirty from mining.
Maximilian Ruffman is Ruff's ancestor. He appeared in Season 5, when Ruff inherited Ruffman Manor from him, but Ruff found out it was haunted. Ruff received an invitation to go to Ruffman Manor, but instead sent out all the kids to spend the night to see if it was truly haunted.
Wink and Dinah Ruffman are Ruff's "long-lost" parents who gave the FETCHers instructions on how to get off Game Show Island. It is revealed in Season 5's finale that they are spies.
Tom and Trixie are Ruff's rivals who are the hosts of Go Get It!, a ripoff of FETCH!. They were actually Ruff's parents, who were working undercover. (Note: A cat named Trixie previously appeared at the end of "Mush if by Land, Mush Mush if by Sea.")
The Canadian Mountie is another of Ruff's cousins. He was seen only on one episode of Season 3.
Professor Fange is Ruff's obedience school teacher. He is seen in two pictures in Ruff Bounces Back. His voice is heard in Ruff's dream at the beginning of the episode giving Ruff a test, the first question of which was "How do you say fetch the stick in Chinese?" The second question was "What are the leash laws in Ecuador?" The last question was "George Washington's dog invented kibble? True or false?" Ruff said he thought Schnauzers were the smartest dogs. He sends Ruff a letter telling him to send his term paper to him but Chet delivers liver causing him to grade Ruff Z- and tell him to send his diploma back.
The FETCH 3000 is Ruff's personal supercomputer, apparently custom-built, that aids him in running the show. It is occasionally subject to breakdowns and malfunctions in the earlier seasons, even with the smallest of problems such as when Brian did very well on a challenge and it broke down due to so many points, but they become less frequent in the later seasons. It can transform into a multitude of applications and machines, shrink into a small cube when not in use, and is semi-sentient, capable of acting on its own.
Ruff's doghouse, while not a character, should be noted in that its actual size is debatable. The first episode of Season 1 has Ruff say that his doghouse is about 6 feet, but later episodes have Ruff's doghouse the size of a truck at the least, especially in Season 4, when the modified doghouse boat is compared to Blackmuzzle's ship. Also, the house is much bigger on the inside than it looks on the outside, akin to the TARDIS of BBC's Doctor Who.
The Irish Center Tenter, Life from West Minister, The Charleton Chihuahua Trilogy, Plan for Cat Benders And The Ten Commands, The Best of the American Poodle (parody of American Idol), Scratching with the Stars (Parody of Dancing with the Stars), America's Got Hydrant (parody of America's Got Talent), & Go Get It! with Tom & Trixie
Noah Ellis - He is full of surprises. He can do stunts on dirt bikes and wants to be a forest ranger.
Taylor Garrson - Taylor appeared previously on ZOOM. She has a sense of humor, an interest in predicting the future, and a knack for getting caught up in some outrageous situations.
Khalil Flemming - Khalil is the youngest FETCHer. He enjoys exotic foods and admires Bill Gates and Oprah Winfrey. Still, Khalil definitely knows how to have fun.
Brian McGoff - He is addicted to sports almost as much as he is hot chocolate. Brian is passionate about lots of things: rock music, ice hockey, water balloon fights, and his dad's pancakes. He's less enthusiastic about dental visits and math tests.
Julia Kardashian-Millstein - She is one of the tallest FETCHers. She can play hockey and likes to dance.
Anna Sheridan - She is the oldest FETCHer. Anna brings maturity and some amazing advanced math skills to the group. She can speak Spanish. Also, she's a real animal lover. She is the Season 1 winner.
Madison Bader ("Madi") - Her talents are dog-walking, and she also thinks she has "mad" dance skills. Madi also got to do a trapeze activity, which she performed for her family.
William Erickson ("Willie") - He loves the water especially while doing all types of water sports. He loves taking things apart to see how they work. Is a child model like Isaac.
Bridget O'Sullivan - She's an expert hula-hooper, skateboarder, rollerblader, and swimmer, but she's never tried a unicycle. Bridget is an athlete and, more importantly, is good at impressions.
Rosario Corso - His nickname is Rizo, because people in his school used to think his name was Rizorio. Rosario loves to sing like Frank Sinatra. Rosario was also a guest juror in the Season 3 episode "The People vs. Grandma Ruffman".
Michael Spencer ("Mike") - Mike loves playing football, and likes being on defense a little bit more than being on offense. Mike also thinks it would be embarrassing if he went to school and forgot his pants. He is the Season 2 winner.
Nina Wadekar - She describes herself as an athlete, kind of, and also says she can do a handstand, kind of. She wants to be a lawyer because she's good in an argument, and she loves to play the violin. Nina considers herself an "amazing" cook, and brownies are her specialty.
Demetrius Santos-Thomas ("DJ") - His teachers call him Demetrius, but his peers call him DJ. DJ loves rap music, and he and his entire family enjoys singing. He can also bend his thumb so it touches the back of his hand.
Harsha Amaravadi - Harsha loves to argue and thinks she'd make a pretty good defense lawyer. She likes to tap things when she gets nervous and speaks Telugu.
Jay Brosnan - He is an awesome lacrosse player, and loves to play the bass guitar with his older brother. If he were a superhero, his name would be Psyshock. He is the Season 3 winner.
Samuel Blumenfeld ("Sam") - He likes Playing drums, hip-hop dancing, and basketball. Sam loves to produce and edit wacky movies with his friends and post them online.
Noel Um - She likes being a cheerleader, writing stories, lip-synching to the radio, and making movies with her sisters Adeline and Charlotte . Noël also enjoys stretching, but when people see her stretch they sometimes think it's grotesque. She hopes to one day hold the world record for being the most flexible person in the world.
Samantha Boucher ("Sammy") - This beautiful FETCHer likes volleyball, dancing, acting, and singing. People call her Sammy the Spiller because she spills everything in sight.
Isaac Bean - He wants to be an emergency room doctor when he grows up so he can fix people. He is currently in the middle of writing a book called "Cliff Mountain." His favorite subjects are Spanish, Math, and Science. He can speak Spanish, German, and sign language. He loves to design web sites. Like Willie, Isaac is also a child model.
Talia Patapoutian - Her talents include acting, singing, writing stories, solving math problems, and making up different hairstyles. Talia thinks she'd make a good entrepreneur and wants to make a perfume that will be able to determine your mood, and then make you happy again if you are sad. She's also a big fan of tennis superstar Roger Federer.
Sterling Singletary - He is one flexible kid! Sterling can put his legs behind his head, raise his eyebrows individually, and fold his tongue in the front and both sides. His favorite subjects are Gym and Reading.
Liza Giangrande - Her hobbies include playing basketball and soccer, acting, singing, and watching old musicals. Her favorite subjects are Social Studies and Science, and she hopes to one day go to Ireland. She is the season 4 winner.
Brian Conroy - He likes playing video games, foursquare, and "any kind of hockey". If he were a superhero, his name would be "Super Brian."
Bethany Owens - She can speak some Spanish and is fluent in Pig Latin. Her other talents include hula hooping, rollerblading, and baiting a hook with a live worm. She also loves singing. She would like to be a doctor when she grows up. Her nickname is Bitty because she is short.
Shreya Viswanathan  - She likes to play the saxophone, piano, and the veena. Her friends call her Shrella Cinderella because she sings a lot and loves animals, just like the fairy tale princess. When she grows up, she wants to be a gastroenterologist, or a doctor who studies the stomach.
Marc "Marco" Frongillo - His hobbies includes playing video games, skateboarding, acting, listening to music, and building things. He once performed in a showcase called "The Music Man" as Marcellus. His favorite subjects are Math and Technology and his talent is imitating Jimmy Stewart and a pig. In the first episode, when Ruff calls the Fetchers, his voice is slightly high-pitched, but in the following episodes his voice is deeper. He is the Season 5 Winner.
Emmie Atwood - Emmie's hobbies are swimming, soccer, squash, and football. Her favorite subjects in school are English, Drama, and Science. She loves animals and nature. Her real name is Emeline.
Marc Prophet  - When he grows up, he wants to travel to Transylvania. He also wants to work in marketing and make commercials. Marc's hobbies include playing video games, collecting comic books, surfing, swimming, and dancing. He has 2 guinea pigs, two fish and an 18-pound cat that drinks out of toilets.
Rubye Peyser - She feels that she can live without TV because you can watch videos on the computer. Her hobbies include solving Sudoku, Ken-Ken, and jigsaw puzzles. She also plays football, softball, field hockey, and yoga. People give her nicknames such as Rukanuba, Rubert, and Rubbie. Her favorite subject is Science. In the first episode appears to be best friends with Emmie.
Jay Ricco - He is an only child, but he is the godfather of his cousin's child. Jay's hobbies include playing guitar, learning how to build websites, and sailing. He is also the lead in a rock band. When he grows up, he wants to be a rock star and a pilot and his favorite subjects are computer, math, and science.
NOTE: Emmie and Rubye are the only FETCHers to know each other in any season before they met at the beginning of the season