Calvin's Alter-egos
Calvin frequently imagines himself as other human characters with super powers, usually to avoid difficult situations (like school tests). His alter egos are: Stupendous Man, Tracer Bullet, and Spaceman Spiff. Stupendous Man is when Calvin puts on a mask and cape and pretends to have super powers, often picturing his mom, babysitter, or teacher as villains. Tracer Bullet is when Calvin is a private eye and takes "cases," usually from his mom or teacher. As Spaceman Spiff, Calvin frequently crashes his spacecraft and is left on alien planets.
On several occasions, Calvin has appeared as either a larger or a smaller version of himself, wreaking havoc as a T-Rex, or crawling across a book page as "Calvin, the human insect." More frequently, he imagines himself as a different creature altogether, in a scenario that parallels his present situation: one strip depicts him imagining himself as Godzilla battling another monster (his mother) while taking a bath.
Read more about this topic: Calvin (Calvin And Hobbes)