Flies

==Reaper==
Picture by FlashMasterXD.
A little fly with a blue ball under its body, can be found in The Depths, Necropolis, Womb or Utero. Very similar to Sucker or Puffer. It slowly follows you. When you kill it, it sends blue technology laser in horizontal and vertical directions. It has more HP than Sucker and Puffer. They appear as an enemy you fight when Little Ghost is killed.
==Troll Fly==
By unknown.
Troll Flies are enemies that spawn in The Depths. When they die, they will create troll bombs in a similar pattern to War or Lokii. 
==Vomit Pooter==
By Mnemonical.
Pooter flies that fire out green bombs instead of red bullets. 
Potato bug doesn't get hurt upon touch. It shoots a whitish yellow liquids at isaac (potato salad) which get isaac stuck in they're spot. It also acts as a creep when the liquids fall on the floor.