Mr. Crazy Person is a semi-recurring character on Animaniacs. He uses the term "man" a lot, as in, "No way, man!" and "You're working your weirdness on me, man!" In all of his appearances, he acts as a sort of gatekeeper keeping the Warners away from something and as a result, Dot always has to use her cuteness against him, which always works.
His character is a parody of Dennis Hopper's character from Apocalypse Now.
He is voiced by Jeff Bennett.