Mr. Blik, Gordon, and Waffle were raised in a mega-mansion by Mrs. Edna Cramdilly who left the three her house and every penny of her fortune when she died. But Mr. Blik, Gordon, and Waffle aren't her grandsons; they're her cats. The brothers live a life of freedom, adventure, and usually total mayhem. Whether they're taking on ferocious bears, sea monsters, zombies, giant robots, hobos, rock stars, or aliens, these wealthy felines just can't keep out of trouble. Their house is normally completely destroyed at the end of episodes, but somehow everything goes back to normal at the beginning of the next episode. The cats also adore Root-Beer.
- Mr. Blik (voiced by Wayne Knight)
- Mr. Blik is the self-appointed leader of the group who's loud, bossy and brash. It is told that a black cat means bad luck, and this is true for Mr. Blik (because he is a black cat), who gets himself into getting major trouble and is prone to near-death injuries. Mr. Blik has yellow eyes and is proud of his newly inherited riches and spends his money on anything and everything that spells respect and power. Mr. Blik is the oldest and always insults his two younger brothers. Mr. Blik's catch phrase is, "Yeah!"
- Gordon Quid (voiced by Rob Paulsen)
- Gordon is a brave member of the Highland Quid clan and acts like he's from Scotland despite the fact that he is not. However, he speaks with a thick stereotype Scottish accent. He is full of heart, has a soft spot for "Human" Kimberly and loves to sing, which quite regularly irritates his older brother, Mr. Blik. He is also an amazing cook, usually cooking Scottish recipes, which a lot of people don't find edible. He has an orange patch on his right eye and is allergic to both broccoli and chocolate which, if touched, will turn him into a "Mr. Hyde"-like monster. In some episodes, Gordon is shown with green-colored eyes, but in others he has blue. Judging from his short tail, he is a Manx. Gordon also has a mission set before him: Get Mr. Blik to do the right thing. Gordon's catch phrases are, "In the name of the Highland Quid Clan", "Feel my sting.", "Great gopher", "Cheer", and sometimes "Pop a Wheelie!".
- Waffle (voiced by Kevin McDonald)
- Waffle is extremely enthusiastic, goofy, cute, funny, and can speak Newtuguese (a language supposedly spoken by newts) as if he were a newt himself. Waffle is a free spirit who is overly optimistic. He often shouts "Splee!" or "Woo Hoo!" when happy and gets super-excited about all things silly. Waffle has been wowed by revolving doors, fingers, bubble wrap and newts. He also wishes roller coasters were public transportation, would eat donuts straight from "donut trees", loves zero gravity basketball and smelling the pictures of flowers on shirts. Waffle enjoys making Armpit Noises. He is a gray American Curl with long, dog-like ears and a long tail. He is the youngest. Kevin McDonald also plays the purple-eyed tallest in the Nickelodeon show "Invader Zim" and Pleakley from "Lilo and Stitch"
- Katilda (voiced by Hynden Walch)
- Katilda is the Cats' neighbor who loves adventures. She appears in "Katilda" and "Blik Mail." It had been confirmed by Doug TenNapel that she would have had more appearances had the series continued. Mr. Blik has a crush on her. Katilda knows this and teases him for it. Katilda also has an active imagination. She also has a doll called Alice Tishmin (which was shown in the episode "Blik Mail"). She is married to Peyton McPherson, he is never showed on any episodes.
- "Human" Kimberly (voiced by Liliana Mumy): Kimberly is a 9-year-old Mexican-American with a lot of heart, a gap in her teeth, and an obsession with unicorns. She is one of the few human friends the cats have. She doesn't think they are greedy, and just accepts her feline neighbors for who they are and sees the good in their fur-covered hearts. She is also completely unaware of that Gordon has a giant crush on her. She has three human friends called Kaitlin, Kaitlyn and Charlotte.
- Hovis (voiced by Maurice LaMarche): Hovis was Mrs. Cramdilly's butler and he's stayed on to see after the cats and collect his measly paychecks (which Mr. Blik signs). He's not exactly thrilled about his new situation, but he hails from a long line of butlers who have served in the house and he honestly believes he's got nowhere else to go. So Hovis puts up with the fact that the former pets have become his masters. Blik barks out orders constantly, Gordon treats him as an equal and Waffle hasn't quite figured out he's not a pet anymore (he still asks Hovis to be let out and scratched behind his ears). His birthday is April 14, 1982, as seen in "Love Jackal". (Hovis' voice sounds similar to that of Shackelford, the butler to the Sherman family on The Critic, which LaMarche also portrayed.)
- Mrs. Edna Cramdilly: Mrs. Cramdilly is the deceased owner of the cats and Hovis's boss. She left her fortune and Hovis to the cats.
- The Chumpy Chump Brothers: The Chumpy Chump Brothers are the neighbors and rivals of the cats. The Chumpy Chumps call Mr. Blik, Gordon, and Waffle "Cats". They have a cat named Bootsy. Tad is the one with the red jacket, Brick is the one with the gray shirt and Luther "Lunk" is the one with the white shirt. None of them had made any friends, until Lunk became the friend of Waffle in the episode "Two Of A Kind", since the two of them are very stupid. They make their first appearance in the "Go Gomez Go" episode, and are voiced by John DiMaggio and Maurice LaMarche.
- Kaitlin: Katlin is a 9 year old Bulgarian-American girl like her friend Kimberly. She was shown in "Tale of a tail" and "Slumber party". She loves unicorns, has braces and short ginger hair.
- Katlyn: Katlyn is one of Kimberly's other friends. She was shown in "Tale of a tail" and "Slumber party". She also loves unicorns. She is African-American and has brown plaits with a rainbow grip. She also wears dungarees. Like Kimberly, Kaitlin and Charlotte, Katlyn is 9 years old.
- Charlotte: Charlotte is Kimberly's 9 year old Swiss American friend who is literally a giant. She has blonde hair and wears a pink dress. She was shown in "Slumber party". She is very large in stature and she never speaks.
- The Mayor: Not really known if he is the mayor, but judges all events. For example, in To The Moon he judges the rib cooking. He gives Mr. Blik the worst ribs ever award. He also judges on Halloween, the best decorated house for the candy bucket.
Gear is the cats' Monster Truck. A simple and solid perk of wealth, this massive machine is adored by the brothers for all its audacious guy-ness. Their pride in blasting down the street aboard their beloved Gear is an equal mix of devil-may-care attitude and obliviousness.
Gear's "personalized" license plate is also written in exactly the same style and font as the logo for the comic Gear which loosely inspired the Catscratch series. Also, in the episode "Mecha Kitties", the robot the cats construct resembles one of the first guardians they encounter in the Gear graphic novel. In the episode "To the Moon", Gear is reassembled into a rocket ship.
Kraken (voiced by Maurice LaMarche) is a giant squid creature who has appeared in two Catscratch episodes. The first was, "Tale of the Tail", the other,"Hi Ho Kraken". It appeared in "Tale of the Tail", as an intercepted catch while fishing out in the sea.
Mrs. Cramdilly's pet cat and Gordon, Waffle, and Mr. Blik's mother. She was only seen in the flashback, and was only mentioned once by Gordon (he comments her name was 'Audrey'). Her current status is unknown, but she is presumed dead. Unlike her three mixed breed sons, who look very comical, she apparently was a serene cat.
Mitchell the MammothEdit
A 1 million year old Woolly Mammoth that was trapped in an ice cube and befriended Mr. Blik. It thought Mr. Blik was his mother so he followed him around in the episode A Woolly Adventure.
A very evil mouse who tricks Waffle into thinking his two older brothers are mice. In the episode "Bringin' Down the Mouse", he is described to be the only uncatchable mouse. (also by Mr. Blik as 'ugly'.)
A short but very mean stray dog (voiced by Clancy Brown) who Waffle meets in the episode "Off the leash" where Waffle did a quiz that said he's a dog. Barkmeat hates cats and finds them tasty. They both are captured and taken to the Dog Pound. They later escape and part ways as Barkmeat gains new found respect for Waffle.
Confirmed by an e-mail from Doug Tennapel, there are a few two-page Catscratch comics in the works for Nick Magazine. The first one appeared in the December/January 2005 issue. The second appeared in the March 2006 issue. The third and most recent one was in the February 2007 Issue.