This looks like a cheat and it's rather usefull, but I'd rather beat the game without it... Frozen Enemies.
I see them move on the minimap, but as soon as they become visible in the main screen, they get stuck in their movement (standing, jumping, walking, casting, ...) and stay that way until they go off the screen again. Allies don't suffer from the same illness.
How did this happen and is there an easy way to get it undone?