Binding of Isaac: Rebirth Wiki

Added in Afterbirth

Lost Fly is a passive item added in The Binding of Isaac: Afterbirth.


  • Spawns a fly familiar that moves in a straight line and attaches itself to the first wall or obstacle it comes into contact within each room.
    • The Lost Fly will then move around the room functionally similar to the Guts Guts.
  • Removed in Repentance If any enemies walk into its path, it will deal 7 contact damage per tick or 105 damage per second.
  • Added in Repentance Lost Fly deals 7 contact damage every 7 ticks, or 56 damage per second. Enemies near Lost Fly will target it instead of Isaac.
  • If the obstacle it is attached to is destroyed then it will continue rolling in the direction it was previously traveling until it meets another wall or obstacle.
  • This item belongs to the Beelzebub set. Collecting three items from this set will transform Isaac into a giant humanoid fly.

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