But they also call him Monster X. (No relation.) Particularly, the title of the movie he's in is "The X From Outer Space," which is hilarious.
Also hilarious is Guilala's design, which looks rather like somebody jammed an alien spaceship on a Godzilla-like monster's head.
What's even funnier, though, is that forty years after the first movie featuring Guilala, they decided it was time for a sequel...
...and there was basically no change to the special effects or the monster.
Possibly the funniest part, however, is that at the climax of the movie, the day is saved by a benevolent giant monster named Take-Majin, who is based on and portrayed by a very famous Japanese filmmaker/actor/comedian/basically everything to do with entertainment named Takeshi Kitano, better known as "Beat Takeshi."
I'm reserving judgment on how great that actually makes Guilala, but it's a funny story if nothing else.