Coil

Coils are indestructible spinal cord enemies found commonly in the Corpse chapter. They are immobile but can zap a constant laser at all enemies in the room (except for other Coils). Coils are often found in rooms containing other invincible enemies such as Wall Huggers or Spikeballs, making them a threat to the player even when the room is cleared. If there are no enemies in the room, Coils will become mostly harmless, though they can still do contact damage. If destroyed via Chaos Card, it will respawn if the player leaves and re-enters the room.