The Catillac Cats
The segment starred a group of cats who lived in a junkyard.
The group was headed by Riff-Raff, an orange short, tough, streetwise alley cat whose main residence was one-half of an old transport plane which stood precariously at the top of a pile of junk overlooking the yard. Riff-Raff was a tough, but suave cat who fancied himself incredibly debonair though he was an alley cat. He often had get famous and/or get rich schemes which formed the basis of many of the episodes. He is shown always dressed with a blue scarf which he wears like a cravat and table leg which he uses as a cane, as well as a sideways baseball cap.
The other cats in the group were Hector, Wordsworth, and Mungo.
Hector, a brown Himalayan cat who speaks with a New Jersey accent, was sometimes depicted as feeling that he should be the head of the group, and becomes so on some occasions, such as the episode "Hector's Takeover". Riff-Raff and Hector's conflicts formed the basis of a number of episodes.
Wordsworth, named after poet William Wordsworth, is a white cat who wears roller skates, yellow headphones, sunglasses, and speaks in rhyme. In the episode "The Big Swipe", his full name was revealed as Wordsworth W. Wordsworth.
Mungo is a large, dim-witted purple cat who acts as a lackey for Riff-Raff. Mungo is often seen wearing a red shirt with a red winter hat. Though dimwitted, Mungo has the skills of an idiot savant in cooking, and has astounding strength and fighting prowess. Mungo is a "gentle-giant" and lighthearted in personality. Mungo has a resemblance to the Blazing Saddles character Mongo. His name may be a tribute to the movie character, or perhaps was influenced by the name of Mungojerrie in the Andrew Lloyd Webber musical Cats.
Most episodes revolved around Riff-Raff's Get-rich-quick schemes or searches for food.
Riff-Raff has a girlfriend named Cleo who lives in a music store. Cleo is a cream-colored cat with long blonde hair, and she looks as though she is wearing a leotard and wears a pair of pink legwarmers. The music store is constantly guarded by a sheepdog named Bush who has long hair and cannot see where he is going (a running gag involved Riff-Raff entering the store, then Bush attempting to chase Riff-Raff out and breaking a musical instrument in the process). In the flashback episode "Christmas Memories", it is revealed that Cleo is, in fact, one of the Catillac Cats herself, even as far as coining the name. On more than one occasion, Riff-Raff ends up 'two-timing' Cleo with another female cat (accidentally or otherwise). In fact, Riff-Raff agrees in one episode, "Kitten Around", to "go steady" with Cleo, but immediately falls for another cat named Roxy. As expected, Cleo is furious and soon gets payback. Strangely enough, they both end up together again in the next episode. Sometimes Cleo is seen with another tomcat that Riff-Raff has to face against.
Another character was Leroy, a dog who also lived in the junkyard. He and the Catillac Cats have a love-hate relationship: Leroy often tried to chase them out, to no avail, though other times he was cast in the light of an ally to them, helping them chase out other outsiders. In the Christmas episode, it is revealed that Leroy is part of a gang put in charge of guarding the junkyard. His name is attributed to the song "Bad Bad Leroy Brown" by Jim Croce.
Leroy is a reddish-brown docked-tail hound with dark brown ears and a large spot over his right eye that resembles a black eye. He also wears a nautical captain's hat.
The red and white Cadillac
The group named itself the Catillac Cats after the red and white Cadillac that featured prominently in their adventures. Hector, Mungo, and Wordsworth were shown to live in the car in the junkyard, while Riff-Raff had a more palatial home made out of a portion of a passenger jumbo jet. The Cadillac itself had the ability to transform into an airboat and a camper. The camper possesses some additional parts, including a stove chimney and a TV antenna. When the car is shown transforming atop its customary mountain of trash, the extra parts are somewhat consistently shown to be shifted to stationary positions at the top of the junk pile (the chimney is even left attached to a small wood-burning stove always seen in the pile just below the car/camper). When the camper form is mobile, however, the parts simply vanish inside along with the other oddities of its transformation. In one episode, its car form was modified into a submarine. Despite usually being depicted with no tires, the Cadillac was also shown to be very fast (perhaps being the fastest car in the city). Its hood ornament was a silver trophy cup, and a blue and white striped wind-sock dangled from its radio antenna. Like all of the characters, the Cadillac was also featured in the credits (shifting from camper to car to boat).
Although both Heathcliff and the Catillac Cats were set in the city of Westfinster, only Hector, Wordsworth and Mungo appeared in both segments. When the trio appeared in Heathcliff episodes, Hector was depicted as the leader of the group. Riff-Raff and Cleo never appeared in a Heathcliff episode (though Riff-Raff is present in a crowd scene cheering for Heathcliff as he fought a dog, and is mentioned a couple of times), and neither Heathcliff nor any other characters from the Heathcliff series (with the small exception of the fish store owner who did have a brief cameo in one Catillac Cats episode) ever appeared in a Catillac Cats episode. The reason is unclear, but some suspect that the McNaught company who owned Heathcliff did not want any outside characters appearing on Heathcliff. Riff-Raff and Cleo were primarily invented by Jean Chalopin and Bruno Bianchi, while Hector, Wordsworth, and Mungo were created specifically so they could appear in either series. The only time in which Heathcliff and Riff-Raff appear on-screen together is in the end credits, when Riff-Raff snatches his hat back from Heathcliff. 
In the end credits and on home videos, the Catillac Cats series is commonly referred to as Cats & Company as seen in the end credits, or Cats & Co. DiC did want the title to be The Catillac Cats, however the company was unsure if the Cadillac car company would have a problem, so throughout most of the first season, the gang name The Catillac Cats was not used until "Hector's Takeover." In the second season, the gang name was used more, suggesting that any concern that may have existed had been worked out.
Early Heathcliff VHS releases used the spelling "The Cadillac Cats", until DiC put out an all 'Cats & Co' tape, which included the first use of the spelling "The Catillac Cats".
When the series was broadcast in French, the theme song gave Heathcliff and Riff-Raff equal treatment, highlighting the differences between them: Heathcliff the domesticated animal, Riff-Raff the alley cat, but both equally cunning and troublesome in their own ways — whereas the American version placed especial emphasis on Heathcliff.
Main voice actors
- Riff-Raff - Stanley Jones
- Hector - Danny Mann
- Mungo - Ted Zeigler
- Wordsworth - Stanley Jones
- Cleo - Donna Christie
- Leroy - Ted Zeigler
- Bush - Danny Wells