Dragon Slayer 4(Legacy of the Wizard) Mimic

ドラゴンスレイヤー4 ドラスレファミリー キャラクター図鑑

Mimic / ミミック

Official illust
Manual / Kadokawa guidebook

JICC guidebook

Basic info

Kadokawa guidebook
It is a monster from the Solomon Islands in the South Pacific, a monster that lives in the Solomon Archipelago, who used magic to breathe life into a treasure chest that a pirate had buried on the island to protect it. It is indistinguishable from a real treasure chest, but occasionally it opens its mouth to breathe.
JICC guidebook
It's a vicious monster that turns into a treasure chest and attacks humans. Especially when there are no monsters, but there are several treasure chests, the first thing to do is to find them. It's safe to assume that most of them are Mimics.