Redmourne the Trivern

In the shadows at the crossroads of imagination and memory lives every soul's darkest fear! …In addition to like, some old bones, boxes of VHS tapes from the '90s, and trash tossed out the window by philandering nobles in carriages. But still! There too is Redmourne the Trivern, the embodiment of fear, who seals lost souls in eternal darkness where they wait in hopes that someone with the power to change fate will save them.

This boss is part of Tiny Tina's Wonderlands: Shattering Spectreglass, which can be purchased individually or as part of the Tiny Tina's Wonderlands Season Pass (a copy of Tiny Tina's Wonderlands is also required to play).