Ekans

Ekans is the first pure poison-type pokemon in the 'dex, so naturally, it's a simple rattlesnake. The typing would feel a little more special if it hadn't been handed arbitrarily to the Bulbasaur line, of course; this makes three distinct poison type pokemon families in only the first nine. Poison is by far my favorite type in the game, but they threw it around like confetti in the first gen, didn't they? I guess that was at least partially for the sake of Team Rocket, the first-gen villains who used primarily poison types.

Anyway, Ekans is a cutie. I love its appropriately expressionless, snakey eyes.