i'm not sure how well-known mad libs are, but i loved them as a kid! the name of the game plays on the term ad lib and consists of a very short story with missing words. the missing words are labeled with their type - noun, adjective, verb, etc... one person asks another for random words that satisfy the grammatical requirements, writes the words into the blank lines, and then reads the silly story with funny, random words out loud for everyone to enjoy.
now that you know the history (did you before? i dont know), you'll understand my enjoyment of today's phd comic: