A scarlet heart mushroom was a large black mushroom that was covered with heart-shaped red spots. When a living creature approached, its heat caused the mushroom's red spots to burst, giving off a cloud of spores that caused blindness that could last for 2-8 days (or until cured with remove blindness or similar). Although they were immune to fire and sonic damage, acid or cold would destroy the mushrooms, while electricity caused them to become dormant for days at a time.