Goblin Deathknight: Hemogoblin/Heemogoblin (hemoglobin used to transport oxygen in the body)
Goblin Priest: Highprofit (High Prophet)
Goblin Warlock: Blastshadow (after an NPC but BA name)
Goblin Mage: Bungledorf (the worst mage ever its a book from dalaran read it and lol)