Minion

Minion: Though powerful, this creature is no leader. It suffers a penalty to all saves and has a wider than normal variance in its attack rolls.

Update 5 has rebalanced attack bonuses and saves of non-named Epic monsters across the entire contents. Instead of tweaking them individually, developers gave this debuff effect to non-named monsters all at once. The effect is believed to be -10 to saves and attack rolls.