2012-01-22
Explanation
The comic presents an alternate reality scenario in which Hitler was captured after World War II and, rather than being executed or imprisoned, was punished by being forced into a demeaning career as a carnival worker. A visitor asks Hitler how tall you have to be to ride the roller coaster, and Hitler begrudgingly holds out his hand and says "Zis tall!" in a German accent.
The humor comes from the absurd juxtaposition of one of history's most notorious figures being reduced to performing the most mundane and lowly job imaginable. The specific choice of a carnival height-check worker is funny because it involves Hitler having to perform a subservient, repetitive task for the amusement of others -- a fitting and ironic punishment. The German accent on "zis" (this) adds to the comedic effect by reminding us of who this person is while he's stuck doing something so trivial.