I originally wanted to go with a more traditional dinosaur-ish design, but had the issue of mixing 2d and 3d.
The Kaiju itself is actually a 3D scene that is rendered to a 2D sprite during the game. Because I wanted the Kaiju to face the way it was attacking, the beam (which is in 2D, overlaid over the sprite) could not come out of its mouth because the 3d model cannot obscure anything above it in the 2d world.
So, the attack origin had to be the topmost point of the Kaiju... and the only fitting creature I could come up was an Anglerfish with the little lantern antenna.
Glad you like it!