Hobbes, named for philosopher Thomas Hobbes, is the deuteragonist of the comics. He is Calvin's stuffed tiger and best friend, who, from Calvin's perspective, is a live tiger and real as anyone else in the strip. The interplay between the two title characters, and the question of whether Hobbes was real or not (Watterson said yes, but only Calvin can see that he's alive) is what gave the strip its unique personality that remained mostly untouched during its decade-long run.