One of my favorite ridiculous Sci-Fi B-movie monsters of all time is the Robot Monster. Much like half the Cantina patrons in the original Star Wars, Robot Monster was just some mish-mash of stuff found in the back of a studio's prop closet, thrown together and called a monster, now big as life and coming to a drive-in near you!
And if a 1950s movie maker can cobble such a threat together, so can a guy with a bunch of Legos!
gorilla suit guy has been one versatile little minifigure! For the antenna, I simply taped two pins to the back of the dive helmet. Simple!
And in case you still don't know who this guy is supposed to be: