About the kind of whale Monstro is.....what species has teeth like that?
Monstro's teeth closely resemble an "Orca" ("Killer Whale"), which is actually more closely related to the dolphin / porpoise toothed-whale family than to most species of whale; I think that the Right Whale still falls into this class as well... Most of the larger whales (Blue Whale, etc) are members of the Baleen family: they have baleen (a big seive to strain the tiny fish / plankton that they eat) instead of teeth.
I think that Disney incorporated the teeth into the original movie to add "danger" to the scenes...
Everyone is trying to figure out what kind of whale Monstro is - from his teeth, to the shape of his head.....etc. I have the answer. HE is a Cartoon Whale!
And when I was a kid, that eyeball on Monstro used to captivate me...I remember standing there at probaby the age of 4 just staring at it...watching it open and close....fascinated me...and Monstro is one of the most fantastic pieces in Fantasyland - I think.