@ Octoboy: Orcas are dolphins? Huh, could've fooled me.
Even with their big, prominent dolphin-y dorsal fins? They're in the family, Delphinidae, so it's pretty safe to say they're dolphins.
As for the temperature Pokemon, I was thinking that if exposed to heat aka Fire type moves it doesn't suffer damage, but rather its speed increases
So, a fire version of motor drive, huh? Interesting, although doesn't mercury expand from heat? Might be interesting to incorporate that. Also, probably give it lots of confusion-inducing moves, considering its infamous ability to cause madness.
I'd love to see a Pokemon based off an okapi! Oarfish's oarfish idea is pretty neat too! Horseshoe crabs would be pretty cool, as well. I know that Kabuto and Wimpod are kinda in that vein of design choice, but just one solely based off a horseshoe crab is what I'd like. Could be Water/Ground or just Water and maybe a special item it secretes/is made from it due to horseshoe crab blood being an important thing in the real world (sterility tests in hospitals).
Not sure what kabuto itself looks like apart from one (I guess kabutops doesn't resemble one, but it's still a different pokémon). The blood idea sounds cool, even if potentially a bit dark. I'd say one creature which has also been pokéfied already, but potentially sold a bit short is odonata. Yeah, we've got yanma and yanmega, but why aren't there any that have naiad forms? I'd love a damselfly pokémon which started as a kickass water/bug type naiad. Maybe with an alternate dragon-type dragonfly evolved form. Not sure what the damselfly could be (it'd suck to get the masquerain treatment and go from water to flying), but I'd say it could easily be pretty cool.
Did I say locust yet? Pokémon's long due a proper orthopteran. The kricket line doesn't look like them at all, they just kind of chirp in a cricket-y way, and that's it. A grasshopper that can actually hop sounds cool. And mole crickets, those are pretty adorable, and would make great pokémon. Also, a flea, I've been imagining flea pokémon since I was a kid. Actually, there aren't a ton of pokémon based on parasites, are there? Imagine a louse pokémon, or maybe even something crazy like a tapeworm pokémon. Or how about a worm pokémon which can give shelmet an alternate evolved form with crazy eyes like those worms give some snails? Might be cool to go with that, then give karrablast an alternate grass-type evolved form in which it steals paras's mushroom, letting paras evolve into a ninjask-esque flying type? I guess it's just a matter of how reluctant the developers are to tow the line towards squick-factor.