To get so drunk you either (A) shit all over hotel bathroom or (B) Have to be wheeled out of Halloween Horror Nights in a wheelchair.
Ryan was so shitvillaged that he drank two more beers before he went to bed (even though Ronnie told him not to) and he ended up shiting all over the bathroom of a Key West Holiday Inn.
After a weekend of drinking beer, eating all those chilli dogs, poutine, and whatever else came in contact with your lips, shitzilla is what attacks you (usually on sunday evening) when you tremble as you approach the toilet.
"Oh man, Shitzilla's on the prowl, can you hear him growling?"
"*Whew* Shitzilla really took a round out of me that time"