Huckit Crab

Huckit Crabs are a species of red crabs within a shell. They sport two yellow feet and a single claw which is used to haul projectiles. The Huckit Crab can toss an unlimited amount of projectiles, usually consisting of sand balls or rocks. The thrown objects travel in a single straight line.

New Super Mario Bros. WiiEdit
Huckit crabs make their first appearance in New Super Mario Bros. Wii. The enemies appear in large quanities in only one area, the third stage of World 4. The crabs can be defeated in multiple ways, including jumping on them, attacking them with Ice Flowers or Fire Flowers. Using the Penguin Suit or Starman are also effective.

The sand balls they throw can be destroyed by jumping on them.

They are set to appear again in New Super Mario Bros. U.