Ishizumai

Ishizumai is a small, orange hermit crab-like Pokémon with large pincers. It has dark, oval-shaped eyes supported by eye stalks. It has a hook-like tail that is concealed underneath the sectioned chunk of gray rock it uses as a shell. This tail is possibly used to keep the rock in place or to carve itself a new home should its old rock get lost. When finding a rock to use as its shell, Ishizumai inspects the rock to see if it can be used, then it digs a hole in the rock's bottom. It can expel a corrosive spray from its mouth to help it carve such a hole, or to mend its shell. If the rock breaks, Ishizumai won't calm down until it can find a replacement. Its search for suitable rocks makes it a natural enemy of Dangoro and Tandon. If it can't find a livable rock, it moves into the ports of a Kabaldon, where it dislodges any stuck stones; in return, the Kabaldon looks after the homeless Ishizumai. (Source: Bulbapedia)