Petey the cat ! ★

Petey is an anthropomorphic ginger cat with black stripes from his shoulders to his tail. As of Dog Man: A Tale of Two Kitties, his right cheek only has two whiskers compared to the three whiskers on his left. Petey's eyes are drawn as vertical black and green eyes. The tip of his tail is flat unlike the rest of his known family for an unknown reason, though Grampa may have something to do with it.

Petey is known for being characterized by his smart wits and his hot-headed temper. He has a way with words in the sense of getting what he wants, which was very commonly used as a manipulative tactic to invoke his evil plans in earlier books as a villain. One of his main weaknesses, however, is getting very irritated over seemingly small inconveniences and immature or ditsy behavior from others. His anger issues have visibly shown to cause him moderate amounts of stress. Also he has impatient mindset, but he has occasionally shown empathy towards others. When Petey unexpectedly became the father of his good-hearted son Lil' Petey, his behavior subtly started to shift. He became more thoughtful and hesitant about continuing his evil schemes and began to care very dearly for Li'l Petey despite the fact that he always tried to morph him into a villainous sidekick before, but Lil' Petey had inspired Petey to decide to finally become a good guy and has been until now. In his lasted adventures, Petey does take some concern in his friends and agrees to help save them when they are in trouble, although it's unknown whether he genuinely likes them or only has care for Li'l Petey's sake.

Almost all of Petey's known history has been revealed in the second half of the Dog Man series, first being mentioned in a flashback from Dog Man: Lord of the Fleas. Petey had been banned from the Critter Scouts after he had been framed for starting chaos while a staff member was absent. He later got his revenge by making a few phone calls to the Animal Rights Union, resulting the Critter Scouts getting shut down within a week. This took place before his father left, as shown by his tail tip still being round within the flashback. Petey was still a young kitten when his father left him and his mother. With hardly anything left, they made their way to the Happy Home Shelter, where Petey spent the rest of his childhood. Petey often had outbursts of anger and wasn't always able to handle the fact that he and his mother could not afford much. But his mother always forgave him. As Petey entered adolescence, his mother tragically passed away of an illness, leaving him orphaned for the rest of his childhood. At some point he was acquired by Dr. Dilbert Dinkle, a criminal who appeared in before in the Invasion of the Potty Snatchers. Dr. Dinkle and Petey the Cat snuck into Jim's Bank, taking a machine that transforms things into water. But then, Petey unintentionally transformed Dr. Dinkle into water, and accidentally destroyed the machine, leaving Dr. Dinkle unable to revert to a human. But, now being made of water, Dr. Dinkle was able to sneak into the vault and steal the money he wanted. Then, Dr. Dinkle returned home and went off to rob more banks, of course not paying the water bill since he was made of water, leaving Petey thirsty. Dr. Dinkle refused to pay the water bill when Petey told him he needed water, so Petey drank him. Then Dr. Dinkle woke up in Petey's litter box, having been turned into pee. Petey began calling Dr. Dinkle "Rip Van Tinkle", much to Dinkle's dismay.

Dr. Dinkle couldn't enjoy his money since everyone kicked him out of their stores for his smell, so in revenge, he made a plan to steal everyone's toilets. So the following night, Rip Van Tinkle put Petey in the Robo Kitty 3000, before he evaporated into a cloud and rained pee. Then the pee drops broke into people's houses to steal toilets for the Petey to destroy with the Robo-Kitty 3000. All toilets were destroyed, including Super Diaper Baby's. Then the drops meshed together to reunite Rip Van Tinkle's body, while Petey stole diapers to sell to the people who got their toilets stolen. Then, when Rip Van Tinkle tried to take Petey's money, Petey soaked him up with toilet paper. Super Diaper Baby and Diaper Dog attempted to end the chaos, only for Petey to evolve the Robo Kitty 300 into the Supa-Mecha Kitty 3000. Super Diaper Baby flew away to buy catnip and pour it inside the robot's control seat. Then Petey goes crazy after a slight sniff of the catnip, detaching the Supa-Mecha Kitty 3000's head. Shortly after his plan was foiled, Petey was sentenced to jail. Petey decided to serve his time in jail and worked to better himself by reading behavior during the time. However, when Petey was finally released, he was surprised to find that despite his efforts, he was refused every job he applied for and nobody gave him a chance. Petey explained to Sarah Hatoff in an interview that this is why he returned to villainy. This eventually led to Petey's first appearance like a villian and his title as the World's Most Evilest Cat.

Petey from the first book gave to understand that he is an inventor and creator of robots with too much strength and intelligence. For example, there is their "super mega vacuum cleaner 2000" which serves precisely to absorb absolutely everything it sees. That machine was created at the time to destroy Dogman. Another example is called "HD-80," whose function is to find people with just a single item or by family history. It also serves to look after his son/clone, Lil' Petey.