Underground River Map (War for the Atlas)

Underground River Map (War for the Atlas) is a map area based on the tileset from The Caverns.

Layout
The map is one long and winding tunnel running along side an underground river. The path splits some times, but soon reconverges, never leading to dead ends. The boss arena has an entrance located at the end of the map.

Boss
It That Fell, based on Q'uru from The Caverns. Repeats the following sequence of maneuvers:
 * Summons a small pack of Plummeting Ursas.
 * Uses and jumps up, disappearing for a few seconds.
 * Lands in the same spot and uses Earthquake again.
 * Enrages for a few seconds.

Boss video
Карта подземной реки (Война за Атлас)