Ratbert

Ratbert is a regular character from the Dilbert comic strip. He was not originally intended to be a regular, instead being part of a series of strips featuring a lab scientist's cruel experiments (Ratbert's name at this stage was XP-39C²). Ratbert soon realized that he was the subject of a hideous macaroni and cheese experiment (the scientist made him eat huge amounts of it and writes in his notebook that it causes paranoia in rats) and escaped, eventually finding a refuge in Dilbert's house. He was not initially accepted by the residents, especially Dilbert, who was highly prejudiced against rats. However, he finally allowed Ratbert to become a permanent member of the household. As a simple rat, and having been specially bred to be susceptible to peer pressure, Ratbert is very gullible and innocent, although optimistic. Sometimes his actions can become quite annoying, such as doing "rat dances". Like Dogbert, he has made inroads into business, once working as an intern, a concierge,... full article at wikipedia