FusionDex

Marotrio regularly burrow through fossil-rich rock layers, picking up the bones of long-dead Pokémon as they do. They wear these bones as armour, protecting themselves from harm whenever they need to surface for food or water.

Because the triplets originally split from one body, they think exactly alike. A Marotrio is the evolved form of a Cubone that has grown tough by overcoming the grief of losing its mother.