The Buff-less Wonder - Plays a class with group buffs, but "forgets" to bring the necessary reagents. Highly skilled at turning a deaf ear and blind eye to buff assignments. If reminded, will proceed to slowly buff people one by one until someone else is overwhelmed by frustration and does it for them. (Kantor, Scarlet Crusade)
Mr. Pick Me! Pick Me!- This guy is online and ready to raid. Always. Need a prot warrior? He's got one. A holy pallie? Check. Problem is, he's really bad. Like bad bad. You keep him in the guild because he's... well, he's always been in the guild. So when your main tank, back up tank, and back up back up tank have vanished Mr. Pick is ready to rock, much to everyone else's horror. (Gaucho, Twisting Nether)
Tootsie - Has a female toon. Claims to be female. Receives many of the benefits that the other females do, people are nice to her; she gets suspiciously good loot. Problem is, she's never posted a picture of herself, and she never talks on Vent. Could she really be a girl? Sure. But who's to know? (Jayne, Mug'thol)
The Dumbest Person On The Planet: No one's quite sure exactly what's wrong with this guy, perhaps human evolution really has come to a standstill. Will be the cause of 60% of your wipes until he gets a /gkick. Tell him to spread out and he'll glue himself to a squishy healer. Tell him to avoid something and he'll stand in it till dead, then complain that he didn't get any heals. Ask him to CC the yellow star and he'll pick the orange circle then claim bleeding wounds debuff on his target. (Zanadune, Vek'nilash)
The Obvious Explainer - This guy has read Wowwiki and probably written some of it. He will stop the raid for 15 minutes before each fight to explain to all the new people (of which there are none) that this guy might produce ground fire once in a while or that the hunter adds might shoot arrows. He'll warn that the boss can hit hard, tell everyone to avoid damage, and remind the healers that they need to keep the tanks alive. It makes you a bit worried that an obviously intelligent person thinks you need spoonfeeding. Sadly, you wipe a lot when he's not here.