Zombie Types Thread - Project Necrophobia

I am thinking that there should be a variety of zombies. These are some ideas I would like your opinion on!

The Shambler:
A basic enemy type which is next to blind and hunts by sound.
Does as the name suggests, and walks in shambling motions.

The Charger:
A more advanced enemy type, capable of covering large amounts of ground in a small amount of time.
It’s sight rivals that of normal humans

The Crawler:
An enemy slower than the Shambler, but crawls on the ground.
Their skin has adapted to camouflage to keep them from being spotted

The (WIP):
An enemy faster than the Shambler, but slower than the Charger.
It hunts by sight and sound, and brings it’s foe’s down with a deadly saliva attack