Gastropod

Gastropod is a hardmode enemy that appears in The Hallow at night. It shoots pink lasers that are extremely fast and thus difficult to dodge. Shooting the Gastropod while it is preparing its laser will cause it to retreat back into its shell and not shoot the charging shot. Gastropods' range makes them difficult to run past and ignore without taking a fair amount of damage while doing so.

Due to the high amount of life and defense, high tier weapons are advised to defeat it.

Besides the Slimer, it is the only flying slime and instead of the Slime or Bat AI, it uses the "Hovering" AI. This is why it doesn't behave like a normal slime but floats and follows the player around.

Trivia

 * These slimes resemble a balloon
 * The actual part of it that looks like a slime is found on the inside, when it shoots a laser.