Morpher

The Morpher is a creature that can shapeshift.

=In fanon games=

In Pikmin: Redemption
The Morpher is a creature in Pikmin: Redemption that possesses the ability to shapeshift into enemies, vegetation, and even leaders and Pikmin. Most of the boss fights in Challenge Mode are against a Morpher. The Morpher is comprised of a gelatin-like substance, and in its default form, is purple and has three eyes, four tentacle-arms, and two legs.

In Pikspore
The Shape-Taker is an unexplained creature in Pikspore that appears only in areas of high supernatural activity. Unlike the Waterwraith, which may simply be the physical form of a psychic phenomenon, the Shape-Taker is a living, breathing organism. Olimar theorizes it to be a being from another dimension, brought to the Pikmin Planet by unknown means. Similar to the Waterwraith, it will appear in a sublevel after a certain amount of time. While the Waterwraith only appears on odd-number sublevels in Realm of Hauntings, the Shape-Taker appears on even-numbered sublevels, where a mysterious whooshing sound marks its entrance. Upon entering the sublevel, the Shape-Taker will instantly take on the form of an enemy found in that sublevel. When the mimic is defeated, the Shape-Taker reveals its true form: a writhing, ever-screaming mass of black, squirming tentacles. The only other feature of the horrifying creature is a pair of glaring, red, almost human-like eyes. The Shape-Taker in its true form will slowly shamble after Pikmin, following them through the entire sublevel if necessary. When it gets close enough, it turns inside-out to reveal its sharp-toothed stomach, where it will flail a long, sticky tongue around like that of the Toady Bloyster to catch and eat Pikmin. Black Pikmin are immune to this attack and they can be thrown at the Shape-Taker's open mouth to damage it. When killed, the Shape-Taker violently coughs out gobs of black slime and crumbles into nothingness, its digestive fluids eating it from the inside, leaving behind nothing but a shiny silver pearl.