World boss of Yaesha biome. Can be accessed after activating the bridge via the water harp.
Must Revive the Doe when given the choice. If you kill the Doe you cannot fight the Ravager afaik.
As for the fight itself. His weak point is his glowing red back. He regularly attacks twice in succession so be prepared to roll a second time straight away.
He summons a few rolling adds in this first half of the fight. He also has a telegraphed shockwave attack that can be dodge rolled. Its fairly narrow but travels far, so a well-timed side roll works well.
In the second half, in addition to the adds he also casts a whirlpool that sucks you in (and possibly drains health?) the whirlpool lasts for maybe 10 seconds or so.
You have two options here. Number 1 is try to run/roll/heal through the whirlpool. This probably won’t end well. I survived this way a few times but only just.
Number 2 and what seems to be a better option is to interrupt/stun him by dealing a large amount of damage.
When he started to cast whirlpool I would activate my hot shot mod and shoot that, followed by my class ability Quick Draw for even more burst damage. This would consistently interrupt his whirlpool cast and leave him open for more damage. Try to finish him off here or regroup for another add clear and stun.