Not to be confused with the Mulligan monster
A blue fly, with a blue heart above it.
Chance to spawn Blue Flies when you damage an enemy.
Blue fly attacks can spawn more blue flies.
No matter how many flies you spawn, no more than 5 will follow you into the next room.
Unlike when Isaac is transformed into Guppy, familiars do not contribute to the spawning of blue flies.
Brimstone beams and Mom's Knife can spawn flies when making contact with enemies.
- Mutant Spider - Will spawn many more flies.
- Technology 2 - Has a much higher chance of spawning flies, due to Techonology 2's high fire rate.
- This item's name and effect was based on the enemy of the same name.