North of the chaos altar in the wildy there are black unicorns. It is multi-combat, so watch out for pkers, but you do not need to take your best armour to fight a unicorn do you? ;) So it's all good. Also, at Entrana there are 3 or 4 unicorns. It's far from any bank, so you'd have to either Glory to Draynor, or use the new nifty hot air balloon network.