Level 2 Spider

Level 2 Spiders wander around the room unpredictably and crawl towards Isaac if he is nearby. They combine the abilities of both the normal Spider and the Trite, though unlike the Trite, they can not leap very far.

Ticking Spider
Ticking Spiders act like Level 2 Spiders, but explode upon death. This can be an especially tricky enemy to battle, as their unpredictable movement can make them hard to hit and they tend to get close to Isaac.

The explosions can help blow up tinted rocks or open secret rooms/super secret rooms.

Migraine
Migraines also act like Level 2 Spiders, but move with slower speed and explode into multiple Troll bombs. They should be treated with great caution when fought.

The explosions can help blow up tinted rocks or open secret rooms/super secret rooms.

Trivia

 * Ticking Spiders used to deal one heart of damage on contact until v1.031. Their collision damage now does half a heart.