Yadorā

A Yadorā (ヤドラー) is a small hermit crab enemy in Wario Land: Super Mario Land 3 that Wario must face in his adventure to steal the treasure of the Brown Sugar Pirates. Yadorā walk back and forth, stopping at platforms' edges. When they reach an edge, they withdraw into their shells and turn around. The crabs are virtually invincible when they withdraw into their shells. The Yadorā can only be defeated by a side tackle to their weak spot: the back; the only other way is with Dragon Wario's breath. If Wario comes in contact with any other part of their body, he will shrink to Tiny Wario.

The Yadorā are also immune to water; they can walk around in it without taking damage. Wario can simply touch their backs to knock them out when they are underwater.

Their name comes from yadokari (ヤドカリ, hermit crab).

Trivia
They have a similar appearance to Spiny Hermits from Super Mario Galaxy 2.