From Sonic Retro
|Game: Sonic Labyrinth
|Affiliation: Eggman Empire
|Hits to defeat: 1
They are big-eyed hermit crab robots that crawl slowly along the ground, stopping at regular intervals to duck into their protective shells. Unleash a Spin Dash when they're shelled up and Sonic will bounce right off. Simply wait for them to come out of hiding before whaling on them.
Their name is derived from "yadokari", which is the Japanese word for "hermit crab".