I have a few in mind, but you could add as many as you wanted.
1: Clicking another non-vampire paralysis the victim for a few seconds, (letting you get away while their stuck standing there, possibly with the tumble affect.) and you gain health+blood if you wanted to add a blood gage or what not.
2: Extra health, SLIGHTLY faster, not the speed of sound, and once again slightly higher jumping.
3:Setting most skin parts to a paler color. (Arms, hands, head, etc etc...)
4:And to top it off, a better climbing ability, if possible the one used by the zombies in Rot's Zombie mod.