Before gaining superpowers, the Copycat was simply an ordinary pet cat. He went to the Lookout and tried to push out the meteor, but a small chunk got lodged in his teeth giving him superpowers. His superpowers are copying the powers of others.
Mr. Nibbles showed a disdain for the Paw Patrol and a wish to have his owner Hailey's attention. Upon hearing about the meteor that gives the pups their powers, he checked it out and knocked off a fragment that lodged into his teeth, giving him the ability to speak as well as all the powers of the Mighty Pups!
The power quickly went to his head as he vowed to become a much bigger story and sensation that the Mighty Pups in order to have Hailey's attention all to himself. Upon meeting Mayor Humdinger, he showed a mean streak in copying what those around him said in a mocking way and took Mayor Humdinger's words as an inspiration to dub himself the Copycat! He accepted Mayor Humdinger's help but treated him as a lowly sidekick and not a partner in crime, giving him the bad guy name, Foggy Boy.
Copycat showed an ambitious and selfish side in stealing objects from around Adventure Bay in order to build his own lookout tower, one bigger than the Lookout of the PAW Patrol, not caring about the damage he was causing, and then sought to acquire the biggest meteor he could so that not only would he have the better tower and bigger meteor, he'd be able to gain even more supwerpowers and become even more powerful, not caring that he was endangering Adventure Bay.
Upon his defeat, he cruelly abandoned Mayor Humdinger and his kitties and made his escape, returning to Hailey's van as if he'd been there the whole time, resuming his normal self as Mr. Nibbles but clearly showing he was still a baddie.
Generally, he has orange fur with cream markings on his muzzle, chest. belly, and paws. He also has green eyes, a pink nose, and a gold tooth, which is actually a fragment of the Mighty Meteor and the source of his powers.
As Mr. Nibbles, he wears a purple collar with a tag that bears a resemblance to the Kitten Catastrophe Crew's logo.
As the Copycat, he wears a purple and silver bodysuit.