The Swarm

The Swarm is a passive item added in The Binding of Isaac: Repentance.

Effects

 * Gives eight orbital flies when picked up.
 * Each time a fly blocks a projectile, it will turn into a blue fly.
 * Each time a room is cleared, spawns an orbital fly.
 * This item belongs to the Beelzebub set. Collecting three items from this set will transform Isaac into a giant humanoid fly.