The Purple Crustacean

 is a purple crab-like sea monster in the movie The Sea Beast.

Throughout The Sea Beast
When Maisie and Jacob washed ashore on an uncharted island, the purple crustacean attacked them. The Red Bluster came to their defense and attacked the Purple Crustacean. It ended up leaving them alone.

Physical appearance
The Purple Crustacean is a purple crab-like sea monster. It has large pincers.

Appearances

 * The Sea Beast

Trivia

 * The team that worked on the Crustacean sought out images of Japanese spider crabs, specifically their mouths. According to character designer Shiyoon Kim, there is a scene in Star Wars where Luke goes through a pit and a creature opens up. The team wanted the same idea, where the mouth opens up and all that can be seen are tiny teeth or claws. They were inspired by crabs, who have little crevices inside their mouth.
 * The design used in the Sea Beast is a little less scary than the actual animal. Director Chris Williams didn't want to make it as scary as real crabs, with several layers of mandibles and tentaclelike structures that push the food inside the crab's mouth.