The spikes spear and kill any enemy foot soldiers or low flying air units present. The only way to destroy one is with air units, but it has the ability to summon a halo of boulders for protection. They freeze an enemy into a block of ice and then chisel away with their ice pick claws. They're not great for moving in on a long-ranged enemy because the yeti will take forever to get there and die first. They're great when closely supported by faster units or aiding in defense.
Nothing can withstand an attack of several silverbacks.
These mutant flying polar bears freeze an opponent with their icy breath and then explode the ice with the next breath. This prevents a creature from fighting back or a wizard from casting spells. They're fast to begin with, but their special feature is a super speed boost for really surprising an enemy. A combination of a ranged melee unit, the warmongers obliterate any nearby attackers whether on the ground or in the air. Their only weakness is they don't have much range so keep them close to you.