From the wowwiki posting
"The" Healer
This person is a good healer. Never lets the tank die. Never drops below 70% mana. Occasionally wipes the raid on farm runs when he gets bored and tries to see how low he can let the tank get before the big heal lands. Likes to see exactly how much of the Tank's HP he can heal in one big crit-heal but doesn't always time things right. See also: The Vindictive Healer.
edit The Vindictive Healer
Usually one of your better healers. Knows everyone in the guild on a first name basis. Has a sharp tongue at times. If you get the better of him verbally, or annoy him in some way, expect to sweat a bit before you get a heal next time you pull aggro. Can sometimes cause wipes if he's talking to the tank.
^me at 70. Holy paladin
And i feel a new one is necessary, as these were level 70 ones on the wowwiki page.
The Trash Tanker
He plays a Ret paladin andhe has 2pc t10. You have no chance of holding aggro and he isn't going to let you. Every paladin has their beacon on him and every shaman is bouncing thier Chain heal through him. As annoyed as they are by him having aggro, trash dies a lot faster when he is alive.