I'd be a happy monkey if all these monsters were put into one MH game.

Small Monsters

So you start off as a hunter looking to carve some guts, this is what you'd be fighting first.

Threatening Monsters

So you've got some skill now and you wanna go after big game, get ready for the cuts and bruises.

OMGWTF Monsters

Now you're famous and you have a death wish, one of these may be the last monsters you ever see. Note: If any of these monsters seem easy, then it SHOULD be OMGWTF.