The Riverfang is the mimic guardian in Ridgeback Highlands. It is currently the final boss in the game (excluding the Boss Fungus and the Summit Whelk). The Riverfang looks similar to Black Recluses. Riverfang is one of the large Mimic Guardians that guards the Boss Fungus in each area and are blocked by a door fungus. After the Mimic Guardian is killed, the Boss Fungus is exposed and can be killed the release a remnant of the original Skystone. Since Mimic Guardians are the final bosses of each area, they are fought during the last missions. There are currently three Mimic Guardians, Flybeast, Great Ferron, and Riverfang. On a map, Mimic Guardians are marked with the same skull as the humanoid mimics (sub-bosses). The missions to defeat Mimic Guardians usually have you exploring a new, la