The Succulent, Meaty Crustacean is a unique Flesh Harvester in Act V of Diablo III. It is found in the Tidal Cave Level 1 under Greyhollow Island, which only appear in Adventure Mode.
In combat, it has the Vortex trait, and two of Jailer, Mortar, Teleporter or Waller. All of these are helpful to it, since it has very slow movement.
A bounty may be offered to kill The Succulent, in which case the secondary objective is to kill 100 enemies. Upon death, it has a chance to drop Helm of Cranial Crustacean.