User blog comment:Emptylord/Blogs/Horde (Gears of War) game mode/@comment-9245010-20130727152702/@comment-3974211-20130727163458

Nah, random would just be a cluster. Even the minions should have a distinctive role. By all means have a minion that randomly mutates over the course of the waves - growing extra arms and stuff, but not literally random abilities.

As in, have a pool of maybe 50 mutations that this mutating unit can "learn". For example:
 * This unit can attack an extra enemy beyond its primary attack target.
 * This unit is immune to knockbacks.
 * This unit takes massively reduced damage.
 * This unit can resist death once, reviving with full health.