XP-39C^2

The original name of the regular character Ratbert from the popular comic strip Dilbert, by Scott Adams. In the beginning, Ratbert was a lab rat who escaped from the lab to seek asylum in Dilbert's house. He is given the name Ratbert by Dogbert, another Dilbert regular, but in a later comic strip is rediscovered by the original scientist who performed experiments on him. In shock, the scientist calls out "Little XP-39C², I'd know you anywhere!"

This name was said by Adams himself to be "great Dilbert trivia".