Yeah, those weird jaws on moray eels were part of what got my attention with them. A lot more interesting anatomy than the average fish. Kind of funny with the sea snake though, given how long skinny creatures fit so nicely into long skinny creatures.

The black swallower is another neat one. There's a lot of really neat things down there. In fact, I just remembered the gulper eel too, and some some angler fish also get the same way. There's actually a really neat image of a 3d-scanned angler fish with a really full stomach (link below) which just shows what it takes to eat something whole. Imagine what a huge swallower of some kind could do.