Fatty Mcgoo Share definition Flag A horribly fat person that is rude and lives in a basement or trailer. Joe: Dude my buddies girlfriend is a Fatty Mcgoo.Bob: Shitty deal dude. Fatty Mcgoo by Wicked Cool awsome MAN!!! May 22, 2009 0 0 Get merch Get the Fatty Mcgoo mug. Buy Now — $32.95 See more merch