Yojiro dropped a charm while running away from an alpha Hippowdon and asks you to find it for him.

The Request

Talk to Yojiro at Bogbound Camp in Crimson Mirelands to accept his request.

Approach Alpha Hippowdon

Go to the area between Gapejaw Bog and Sludge Mound, and approach the Alpha Hippowdon. There will be a cutscene, and you will have to battle Hippowdon.

Reward

You will get 5 Iron Chunks and 1 Grit Gravel after you defeat Hippowdon.