Binding of Isaac: Rebirth Wiki

Added in Repentance
Disambig-dark.png This article is about Psy Fly, similar in appearance to Obsessed Fan.

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


  • Spawns a fly orbital familiar that chases and blocks enemy shots.
    • After a certain amount of shots are blocked, it enters a short cooldown period where it still blocks shots, but does not actively chase them.
  • Psy Fly also deals 1 contact damage to enemies per tick (15 per second).
  • Turns some Fly enemies into friendly Blue Flies if it touches them while blocking shots (but not on the return trip).
  • This item belongs to the Beelzebub set. Collecting three items from this set will transform Isaac into a giant humanoid fly.


  • While Psy Fly is an effective means of projectile protection, it is not immunity, and recklessly wading into a barrage of shots can easily result in taking damage.
  • Psy Fly will block most types of projectiles, not just red bullets. This includes the fires from Mega Satan Mega Satan phase 2, the bone projectiles Bony Bonies throw, or even the rocks that the Kineti Kineti throws at you.
  • Enemy Flies touched by Psy Fly can die if their HP is low enough, which does not convert them into Blue Flies.

In-game Footage[]


  • This item originates from the Antibirth mod, but it was unobtainable due to a bug. It also had a scrapped secondary ability that made Attack Flies turn into Blue Flies when encountered. Psy Fly was orignally unlocked by completing Isaac's Awakening (challenge #39).



PC 6TD6 SXQV (Treasure Room Treasure Room adjacent to spawn)

PC K9XD FZV7 (Treasure Room Treasure Room adjacent to spawn)

PC X1V7 BKFZ (Treasure Room Treasure Room adjacent to spawn)

PCN9HM QYYQ (Treasure Room Treasure Room adjacent to spawn)

PC Hard mode only W37C 0FGF (First floor Treasure Room Treasure Room)

PC Hard mode only CQ7M M8HQ (First floor behind some rock)