Most boss transformations in a run-and-gun shoot-'em-up videogame

As if Cuphead – released on 29 September 2017 for Xbox One and PC – wasn't challenging enough, Studio MDHR fiendishly decided to keep players on their toes by having the majority of the shoot-'em-up's bosses transform into other unique forms during fights. For example, Goopy Le Grande – the first boss most players will face – transforms from his "small slime" form into "big slime" and then into his "gravestone" form during the course of the battle, with each form having a distinct pattern of attack. In all, the game's 36 bosses have a combined 43 unique additional forms they transform into. Baroness Von Bon Bon has five unique transformations, the most of any of Cuphead's bosses.

If you were to take the initial form of each boss into account, Cuphead would have a total of 78 unique boss forms.