Meow Monster Share definition Flag A person, or sometimes thing, who comes in the middle of the night and steals yayo out of your room. This sucks, last night the meow monster came and now I'm out 60 bucks. Meow Monster by Woofmeow3 December 19, 2010 0 0 Get merch Get the Meow Monster mug. Buy Now — $32.95 See more merch