Penelope

Penelope is a mouse from Holland of the world of Sly Cooper who led a double-life as an infamous pilot known as the Black Baron. She was the founder and reigning champion of the ACES dogfighting competition. She was later unmasked by the Cooper Gang, after which she joined them as their RC specialist up to and during their mission to access the Cooper Vault. During this time, she developed a relationship with Bentley, and after the Cooper Vault job, the both of them constructed a time machine. It was at this time that Penelope turned against the Cooper Gang after believing that Sly and his values of "honor" were a bad influence on Bentley, believing that she and Bentley together could rule the world through weapons design and trade. Thus she disappeared and joined forces with Le Paradox in an attempt to sever all of Bentley's ties to the Cooper Gang and unlock what she believed to be his full potential, which was implied to be world conquest, as she gave him access to time travel. She was defeated by the Cooper Gang in the time period of Sir Gallant Cooper under the identity of the Black Knight and imprisoned, but later escaped and remains at large as a fugitive while leaving marks on walls for Bentley. She was voiced by Annette Toutonghi.

Role in the series
Penelope still remained a villain for a while until it was revealed that she was brainwashed by Clockwerk's former python advocate Python Lord Kailass, with his ability to hypnotize people to doing evil deeds, as revenge against the Cooper Clan. Though even after this was revealed, Penelope would remain roughly an antihero until Bentley finds a way to get her back.