Crab Spirit

Crab Spirit (タラバガニの精霊, Tarabagani no seirei, lit. "Spirit of Red King Crab") is a spirit of a red king crab, that is Kouji Yamada's Guardian ghost.

About
Apparently he got along well with Damayaji, because he looked like a hermit crab. After Damayaji's death, both ascended to heaven together rather quickly.

Anime/Manga Difference
See More: Centipede Spirit

In the anime Yamada has a large teal green centipede-like spirit instead of the Crab Spirit