List of characters in Foster's Home for Imaginary Friends

This is a list of characters seen in the American animated television series Foster's Home for Imaginary Friends.

Main characters

• Mac – A bright and somewhat shy 8-year old boy (9 as of "The Bloo Superdude and the Great Creator of Everything's Awesome Ceremony of Fun That He's Not Invited To"). Mac almost always seems to know what to do when there is a problem. He enjoys visiting Foster's and all his friends who live there. Mac becomes extremely hyperactive to the point of a rabid mania if he eats sugar; once in this state, he will often become obsessed with seeking any other source (and will also sometimes run around naked or in his underwear). Mac also has a crush on Frankie. He is voiced by Sean Marquette.
• Bloo – Mac's 5-year old imaginary friend and best friend who resembles a simple, domed cylinder. Bloo is egocentric and superficial almost to the point of psychotic delusion, which somewhat adheres to the theory that he is basically Mac's id personality. Bloo is also self-centered and enjoys pulling pranks. However, he still has a good heart and sometimes apologises for his actions. He loves paddleballs, even though he can't make the ball hit the paddle (he constantly insists that it's because the paddleball is broken). His full name is "Blooregard Q. Kazoo". He has become increasingly more mischievous over the run of the series and is shown to have bad memory some of the time. He is voiced by Keith Ferguson.
• Frankie – Madame Foster's 22-year-old granddaughter. Frankie is the caregiver at Foster's and helps keep everything in order. In spite of Mr. Herriman's fussiness and fixation with rules and cleanliness, having to take care of everyone and everything in the house, and Bloo's mischef-making (all in which cause her tremendous stress), she is usually very friendly and easy-going. And though she may seem somewhat like a surrogate mother to Mac, she is more accurately described as a big sister to the imaginary friends. She is voiced by Grey DeLisle.
• Mr. Herriman – A British, man-sized, bipedal rabbit friend imagined by Madame Foster. He wears a tuxedo coat, white gloves and a stovepipe hat, as well as a monocle over his left eye (though it is sometimes seen over his right eye). He is in charge of the house (the "President" of Foster's), is extremely strict about the house rules (or just politeness and order in general), and is often found punishing Bloo for his various misdemeanors. It was revealed in "Busted" that the reason Mr. Herriman is so hard on Bloo is because he feels that, given that he is allowed to stay at Foster's even though he still has an owner, he has already broken one of the main house rules. He is extremely fond of his creator Madame Foster, harboring great respect and loyalty to her, even at her most prominent levels of unabashed pep and energy. On the other hand, Herriman has a love/hate relationship with Frankie, usually working with her to preserve order at Foster's, yet just as often scolding her for what he perceives (often inaccurately) as "laziness" and "immaturity" from her part. However, at the end of the 90-minute special "Destination Imagination", Herriman admits he was wrong and finally comes to respect and appreciate Frankie. He is voiced by Tom Kane.
• Madame Foster – The founder of Foster's. Madame Foster is elderly but has child-like boundless energy, and enjoys life to the fullest. Her imaginary friend is Mr. Herriman who she imagined when she was a child and never gave up. Like Bloo, Madame Foster occasionally becomes hyperactive and mischievous. However, there are times she's shown to be the wisdom of the house. She is voiced by Candi Milo.
• Wilt – A very friendly, very tall, red imaginary friend with a stubby left arm and crooked left eyestalk (which he describes as "wonky"). However, in "Good Wilt Hunting," it is discovered that he was not always this way—He was injured in a fateful accident during a basketball game, leaving his arm crushed and his eye injured. Wilt exhibits consummate good sportsmanship, which he applies to every part of life he can. He's extremely courteous to a fault, often willing to help anyone, fix anything, and perform anything asked of him, (even if he has to go entirely out of his way to do so), and apologizes almost constantly (he is known for saying "Is that ok?", "Sorry!", "I'm sorry, but", "I'm sorry is that okay?", and "I'm sorry, but that's not okay!"). He has a big heart, is cool and collected, and on very rare occasions can be moody or short-tempered. His name is a homage to NBA star Wilt Chamberlain. Wilt was shown to be created by Jordan Michaels, a basketball star (and a homage to Michael Jordan). He is voiced by Phil LaMarr.
• Eduardo – A Spanish guardian friend. Despite his large size, overwhelming strength, and menacing demeanor, Eduardo is quite docile, timid, and compassionate. He has a toddler-like nature, crying at minor negative occurrences, and being scared of almost everything. However, he can be ferocious if angered or in the circumstance that danger befalls his friends. Eduardo has a fondness for potatoes and his cuddly toys. His creator, Nina Valerosa, is now a police officer. He is voiced by Tom Kenny.
• Coco – A bird-airplane-palm tree friend who can only say (or write) her name at various speeds and different emphases. A talent unique to her is her ability to lay colorful, plastic eggs containing a plethora of objects from customized baseball cards to money, at will. Mac, Bloo, Eduardo, Frankie, Wilt, and others usually understand her when she speaks, and often translate for her (though Wilt once admits that he has no idea what she attempts to convey). Despite her helter-skelter appearance and quirky behavior, she can demonstrate a perceived intelligence, principle and kindness. No one knows who her creator is as she was found on an island by two scientists. Coco is voiced by Candi Milo.

Recurring characters

• Cheese – A simple, pale-yellow friend who debuted in "Mac Daddy". Cheese was thought to be an imaginary friend accidentally created by Mac, but was actually created by Mac's neighbor Louise. He appears to be somewhat madcap and dim-witted, often saying incoherent or non-sequitur phrases, and breaking into sudden bouts of screaming when frightened or when he doesn't get his way. Cheese likes goldfish crackers, cereal, juice, chocolate milk (although he is lactose-intolerant), and so on. His name can be paired off with other characters' names to make puns-of-sorts ("Mac and Cheese"/ Macaroni and Cheese, "Bloo Cheese"/ the kind of cheese, and "Cheese Louise"/ the expression "Geez Louise!"). In the series finale "Goodbye to Bloo", he comes to live at Foster's, much to the residents' surprise/horror. Cheese is always considered to be an annoyance, but is treated like a friend by Mac's friends in "Infernal Slumber". He is voiced by Candi Milo.
• Goo – A hyper-imaginative, hyper-talkative 10-year-old girl who visits Foster's. She first appeared in the episode "Go Goo Go". Her parents allowed her to name herself when she was a baby resulting in the full name "Goo Goo Ga Ga". Goo enjoys playing games such as Checkers and Truth or Dare, but she does not know how to play and Mac is the only one who notices. In her first appearance she constantly created friends and finally stopped at the end. However, she has still created a few by mistake or to help on rare occasions. Goo is voiced by Grey DeLisle.
• Terrence – Mac's 13-year-old brother. He enjoys bullying Mac, and coming up with various schemes to make Mac's life miserable. His stupidity always gets the better of him, making him easily outsmarted. He is voiced by Tara Strong.
• Duchess – A "high-maintenance" friend who is pompous, rude, and lazy up to the point she orders Frankie to open her eyelids for her first thing in the morning. After conspiring to get rid of Bloo, she was not kicked out of the house, but forced to stay as punishment when she yearns to leave. She considers herself superior to all the other imaginary friends, is extremely negative towards everyone, and never says anything nice (despite this, she has helped someone in four episodes but only to help herself). Whenever Duchess turns on the spot, her entire body pivots like a sheet of paper being flipped, revealing that she is two-dimensional (however, in the pilot movie "House of Bloos", she was not two-dimensional). Her full name is "Her Royal Duchess Diamond Persnickity the First, Last, and Only". She is voiced by Grey DeLisle.