Sorry, the Correct Answer is "Scatophage"

Woman #1: You just know that's going to be David in a few years. The one with $6 million just sitting in the bank.
Woman #2: I know. You wouldn't expect it of him, though.
Woman #1: Yeah. I'm still trying to figure out what kind of insane he is.
Woman #2: Hmm. Manic, maybe?

--6 train