Jack is an anthropomorphic cat, Oggy's cousin and the deuteragonist from the animated series, Oggy and the Cockroaches.
Jack is a real time bomb on four paws and the ideal witness to all of the horrors that the roaches will inflict on Oggy. Also, he often finds himself building huge machinery such as roach-catching contraptions, most of the time resulting in backfiring and he is also very interested in chemistry.
Jack is aggressive, violent, short-tempered, sometimes lazy, obnoxious, arrogant and is always focused on getting rid of the cockroaches or doing something selfish.
He also sometimes bullies Oggy, either moving him when he's in front of the TV, trying to beat him in a race, or just plain going insane. He is perhaps the easiest target in the show, mainly because his rage gets him too unfocused on either getting rid of the cockroaches. Even though he might be a little insane, he's mainly there to pick up Oggy's pieces or bust him out of trouble.
As keyed up as an over-wound alarm clock, Jack is quick to take affront. What's more, he suffers from abnormally high blood pressure. In other words, he could explode at any moment.
He is a slender and muscular olive-green furred cat with hair strands, white paws, hands, pointed ears with ear hair and pointed tail, a red nose, black bags on his yellow eyes, whiskers on his grey cheeks with yellow spots.