The Obsidian Dog behaves as a statue and will only attack (and be vulnerable to attacks) if the player stands still for a few seconds close to the statue.

Location:


Bestiary entry and monster screenshot:

The Giant Rat spawns in a secret room right after a trap. To access this room the player must destroy a breakable wall in the room just to the right of it. The monster runs a few seconds after the player gets close to it. Might require a few tries, but should be easy to kill with a bow.

Location:


Bestiary entry and monster screenshot:

The original information on which this guide is based was found in the topic "Anyone know Monster List #21 and #56 are?" from the Steam Discussions page for this game. An special thanks is due to user 冰霜之孤狼1993, which was the one who answered said topic.