Kwolok is a character in Ori and the Will of the Wisps. A giant toad, Kwolok is called "Lord of the Marsh" or "Guardian of the Marsh" and described by The Moki as kind and helpful. Kwolok dwells in Kwolok's Hollow, near Inkwater Marsh.
Kwolok helps Ori advance in their main quest in finding Ku by tasking them to purify the waters at The Wellspring in order to reach the Silent Woods.
After Ori and Ku's encounter with Shriek left the latter at death's door, Kwolok resolves in helping Ori restore the land by finding Strength of the Forest in Luma Pools. After he finds it, Kwolok becomes corrupted by the Stink Spirit, which previously resided in The Wellspring, and Ori is forced to fight him.
After Ori defeats Kwolok and the Sitnk Spirit, Kwolok frees himself from the vile creature's control and crushes it for good. However the toad guardian sustained fatal injuries from the battle, and with the last ounce of his strength, he requests Ori to watch over Niwen and the Moki. Kwolok then vanishes into the light as he succumbs to his injuries.
Boss Fight Walkthrough Video
ORI AND THE WILL OF THE WISPS- Kwolok Boss Fight (Timely Demise Achievement)