The Challenger's Deep bestiary is the second bestiary you can complete while visiting the cave system under Rosilt Bay in Roblox's Fisch. After getting a submarine upgrade in Volcanic Vents, you can ...

The Volcanic Vents Bestiary is one of the five bestiaries brought by the Mariana's Veil update to Roblox's Fisch, and it contains unique species of lava fish. Among other sub-locations of underwater ...