A Bizarre Journey Roblox Wiki

Its a new boss with 790,000 hp,its at the Underworld Dimension, you get teleported there by clicking Odd_developer

It drops: Shattered Flame , Saitama's Cape, Glitched Lightning

It appears that Glitched Lightning is most common, followed by shattered flame and Saitama's Cape.

How the boss looks like:

Underworld boss Itself (lol)

Note: This boss was removed.