The act of taking filling two shot glasses with alcohol, dumping them both in your mouth, and then holding the glasses over your eyes like goggles and making monster noises. Usually a residual amount of alcohol will actually pour into your eyes and your eyes turn bloodshot and burn and you'll start actually screaming. This is knows as "Full Monster".
Bro 1: Rawrrr I'm the shot monster!
(vodka splashes into eyes)
Bro 1: AHHHHHHHHHHHHHH! (Full Monster)