Ok but, Gaster Blasters are snake skulls. Snakes unhinge their jaw to fit in food that is larger than their head and blasters unhinge at the same place to fire a beam.
This isn’t quite true, I work with snakes and handle them, and the unhinging and dislocating of jaws is more of a misunderstanding. The jaw bones don’t swing open or leave the “hinges” and the jaws don’t break, they simply are made of small bones and stretch, the jaws are seperate in the middle and connected with stretching connective ligaments, and their teeth in the lower jaws do not rotate outward or inward.
They will often appear to yawn after swallowing a large mouse and move their jaws around, but that is stretching, not resetting the joints or “hinging”.
Snakes also don’t have the right dentation or nasal cavity or Sagittal ridge on the top/back of the skull for the Gaster Blaster. In snakes instead of the jaw opening outwards when they eat, if you could see the bones and ligaments you would see them bend and stretch apart in the shape of what’s being swallowed, it’s easy to see when they eat eggs. The other funny thing is that snakes don’t have to open their mouths wide to make loud noises, they hiss with their mouths shut through the hole in their mouths that allow their tongue to flick out and back in to taste the air and “smell”.
Gaster Blasters most closely resemble canid skull, a mix between an African hunting dog and a large domestic dog and a grey wolf. With no side or full frontal angle it’s impossible to rule out domestic dogs. You can see the full post on it here http://undertale-science.tumblr.com/post/134555887503/thanks-to-a-lot-of-hard-research-i-have