Big Spiders are larger versions of normal Spiders added to the Wrath of the Lamb DLC. They look like regular spiders, but with a large black abdomen attached.
They behave in the same way as the regular spiders, having the same movement speed and erratic behavior. However, they have almost more health than regular spiders, and on death, they will split into two small spiders that have decreased health. The smaller Spiders will not spawn on a B. Spider's death if they are killed by a large explosion or with The Virus.
- They're also spawned by The Wretched or black champion variant of The Widow during the fight.
- In Rebirth, they can be spawned by the Nests after death.