Flies
Flies are enemies that buzz around the room, erratically hovering towards Isaac.
This page is about Flies added in Fiend Folio. More information about Flies in general can be found in the vanilla page.
Shot Fly
Shot Flies fly slowly after Isaac and will make sharp turns, following a grid-like movement, while attempting to align with him. Upon taking damage, the next time they are lined up with Isaac, they will begin a rapid charge in the cardinal direction closest to Isaac. They will die on impact with a wall while charging.
Shoter
Shoters are 
Moter variants of Shot Flies, while following the same grid-based movement pattern. Upon taking damage, the next time they are lined up with Isaac, they will split into 2 charging Shot Flies in a V pattern, oriented in the cardinal direction closest to Isaac. If killed before charging, the 2 charging Shot Flies will be shot horizontally to the left and right.
Ticking Fly
Ticking Flies are the 
Ticking Spider counterpart to Flies. They behave like 
Level 2 Flies but explode on death.
Custom Moter
Custom Moters are a fairly rare Moter variant. They behave like their regular counterparts, but can be comprised of 1-16 
Attack Flies stacked together. They can take any shape within a 4x4 grid with the shape being determined by the room layout. Additionally, if a Custom Moter spawns adjacent to another Custom Moter, they will merge into an even larger Custom Moter, allowing for practically infinite possibilities and shapes.
When a Custom Moter dies, it will split, shooting out a random selection of singular Attack Flies and smaller Custom Moters in all directions.
Square Fly
Square Flies are variants of Level 2 Flies that chase Isaac while following square paths, periodically making 90-degree turns. When moving towards Isaac, they will fly faster, and when moving away from Isaac along the path, they will fly slower.
There are two variants depending on their color: blue travels clockwise and yellow travels counterclockwise.
Lightning Fly
Lightning Flies fly towards Isaac and periodically become electrified for a few seconds, flying faster and becoming invulnerable while in this state.
Due to the periodic pace at which they switch between states, swarms of Lightning Flies will all become electrified at the same time.
Golden Fly Bomb
Golden Fly Bombs behave identically to 
Fly Bombs but each time the golden bomb it drops explodes, it turns back into a Golden Fly Bomb. If it comes into contact with Isaac, it explodes and disappears for a moment before spawning again at its original position, indicated by a gold sparkle effect.
It will reform indefinitely until the room is cleared.
There is a rose gold-colored variant of the Golden Fly Bomb that behaves identically, but the bombs that it drops can be picked up and thrown like 
Throwable Bombs.
Ring of Ring Flies
Rings of Ring Flies are a variant of 
Ring Flies all connected in a circle. They fly towards Isaac while moving in a counter-clockwise path and upon death, separate into 8 Ring Flies.
Bead Fly
Bead Flies are pink variants of 
Army Flies that are all connected by a pink wire. They travel together in a connected line and can only move in any direction other than cardinal — making waving and arcing movements as a result. They are found most commonly spawned by 
Ripcord.
The leading Bead Fly in a chain will have a unique ring appearance, but otherwise behave identically.
Trivia
- Ticking Flies are designed as a counterpart to
Full Spiders, who originated from the Reheated spritesheet and were added as a joke, but were eventually put into some rooms. - Lightning Flies are likely named after lightning bugs, another name for fireflies.
- Custom Moters were originally an enemy in The Devil's Harvest.
- There are 2,081,050 possible variants of Custom Moters.
- Golden Fly Bombs were originally a part of the Guwah Greatures MOD before being ported to Fiend Folio.
- Golden Fly Bombs were added in The Spookaween Update.
Gallery
An electrified Lightning Fly.
Early version of Clockwise Square Fly.
Early version of Counter-Clockwise Square Fly.
Old version of Clockwise Square Fly.
Old version of Counter-Clockwise Square Fly.
AB+ sprite of Lightning Fly.
