When damaged in melee by an attacker, a spiderdemon very occasionally becomes frozen in place, unable to walk or fire. Because monsters tend to repeat melee attacks until the target moves out of range, the spiderdemon then continues to take damage without retaliating. This stops only when the spiderdemon dies, or when a third party intervenes by assaulting one of the participants. This bug may also, but less often, affect smaller monsters such as the arachnotron.