In WoW, only Sand and Undead trolls are new. You can read about Sand trolls in WoW wiki. And Undead trolls come in many variations - Scourge Trolls(trolls killed and raised by the Scourge), Mummified Trolls(trolls from the Sunken Temple of Atal'hakkar who got drowned and somehow returned to life) and more. Also there are Dire trolls(huge, hulking trolls who hardly actually resemble trolls) but I don't know much about them either.