The following is a list of each SP citizen, and their character in WoW:
Cartman's character is a Dwarf Warrior named bigboNed3.
Kenny's character is a male Human Hunter.
Kyle is a female Human Mage with a Arcane/Fire speciality.
Stan's character is a Male Human Warrior named Luvs2SPWG (or Lovestospooge).
Randy's character is a Male Human Warrior, even though he says he is a Hunter.
Craig's character is a Male Gnome Mage.
Tweek's character is a Male Gnome Warrior. His character is seen only when on fire.
Clyde's character is a Male Night Elf Hunter.
Ike's character is a Male Human Priest. He is wearing the Devout Set (without the head), an end-game dungeon set for priests.
Timmy's character is a Male Human Priest.
Butters character is a Male Dwarf Warrior and looks the same as Cartman. He gets told to change, and isn't seen afterward.
Jimmy's character is a Male Night Elf Hunter.
Token's character is a Male Human Rogue.