List of Characters

Main Characters

 * Billy Colas - A Tiger-like Cat who was once a young boy until he was hit by a car in the comics. In the cartoon, He becomes a cat because of a magician.
 * Mr. Hubert - A White Cat with a blueish tailtip and wears a green bow-tie around His neck.
 * Queenie - A White Cat with a pink bow around Her neck. in the French Comics, Her name was Cha-Cha.
 * Jumbo - A Pigeon who thinks He's an Airplane.
 * Sanctifur - A Grey Cat with a scar on His left eye, who associates Himself if Len and Des' bosses.

Recurring Characters

 * Len and Des - Two Men who try to get money in dishonest ways. (They appeared and died in the first comic issue)
 * Blackie - A Black Cat with a stitch on His nose and leader of His Gang
 * Tabby - A Brownish Cat with Black stripes and one of Blackie's gang members.
 * Manx - A Grey Manx Cat and one of Blackie's gang members.
 * Grosmeyer - Chef and owner of His restaurant, who doesn't mind giving scraps of food to cats visiting.

Minor Characters

 * Ali Kazam - The Magician who turned Billy into a cat. He makes a re-appearance on Billy's Last Chance.
 * Mr. Colas - Billy’s Father.
 * Mrs. Colas - Billy’s Mother.
 * Marie Colas - Billy’s little sister.
 * Kittens - Three kittens who went missing and is currently at a pet shop. in the first TV special, They have Manx for an Uncle.

One-Off Characters (In order of appearance)

 * Dandelion - a Grey-ish cat with a green collar who belongs to Ali Kazam.
 * Arthur - Queenie's caretaker and a security guard for a museum.
 * Snapper - An Alligator from Billy's past who hates dogs.
 * Dennis - A Laid-back Cat with a Surfer-like accent.
 * Tigerlily and Lord Milla - Two cats who are smuggled from their home countries to be sold to catless couples
 * Delilah - A Siamese Cat who is lovingly pursued by Mr. Hubert and Sanctifur.

Villains

 * Moonie - A Canine who is Leader of the Dead-End Dogs.
 * Sausage - A Large Bassett Hound who hates cats. (Was a Major character in the comics)
 * Archeologist - Ordered Len and Dez to steal a gold cat statue,
 * Grotz and His Assistant - Invented an earthquake machine to ransom the city.
 * Slasher - An Affenpincher Dog, and a henchdog to Grotz.
 * Captain Grunge - A ship Captain who smuggles cats from all over the world.
 * Rat King - A Big Rat who lives in Capt. Grunge's ship.
 * Professor Asare - A Scientist who intends to control animals with a remote.
 * Mr. Gourmand - A Pet Food owner who used Mr. Hubert for commercials.