You see Poison Spider
Notes
Poison Spiders are a bit stronger than regular Spiders in that they hit harder and can poison you with venom a little stronger than that of a Snake's. It is not advisable to attack one below Level 4. Giant Spiders summon up to two Poison Spiders to break shielding and enable much stronger hits.
Abilities
Melee (0-20), Poison with 1 hp per turn (15-20 turns) or starting with 2 hp per turn (20-25 turns, 21-30 hp).
Damage Taken From Elements
Physical 
Death 
Holy 
Ice 
Fire
Energy
Earth
Behaviour
A poison spider will retreat at 6 (23.08%, red) health.