It fastens around your face, though, so you can still see and (more importantly) eat.
With a regular costume and regular mask, you wouldn’t be able to put anything in your mouth. Say you want to capitalize on the renewed interest in dinosaurs this year by dressing up like the fearsome T-Rex at your new costume party, but you also want to be able to easily snack on all that good candy.This hat looks just like a real live T-Rex head, so much so that children will probably run screaming from you while every archaeologist in the 5-mile radius will come running.