What is a Vulture? I really don't know.

As in the bird? It's a bird that likes to eat on dead corpses.

It's also an unit on starcraft, doing good dmg and fast, but weak.

Is there like a list of them somewhere?

Here is the link to wiki : http://en.wikipedia.org/wiki/Vulture
And a litle list of african vultures: http://www.africanwildlifeguide.com/species-guide/birds/birds-of-prey/vultures