When you do the quest On Ruby wings On Ruby Wings - Quest - World of Warcraft you get a drake with many LP to killing questmobs, but this drake can auto-attack player from the other faction (when PvP is activated).
It's really fun because the drake do 900-1000 dmg per hit and when the player from the other faction attack, the guards will attack him.
Screenshots:
http://img167.imageshack.us/my.php?image=expltzb1.jpg
http://img221.imageshack.us/my.php?image=expltehrenu0.jpg
hope you like it
by bdown