Reprobate

The "Reprobate" takes on many forms. The forms it takes can deal damage to it if they happen to fight back, but it is unlikely that it will die due to this. It is a somewhat amorphous variety of sporovid that takes other creatures, such as wildlife, Pikmin, assorted flora, and even other sporovids, and physically attaches them to its own body or within it. It can be found attached to just about any surface, walking around, climbing walls, and some even floating in water. It tends to attempt to assimilate creatures with projectile or long ranged attacks, though it will also do so to short ranged or non-attacking creatures as well. It has a wide array of appearances, but it's basic form, which can be found in between the creatures that it has taken the shapes from, appears to be a tough, spongy mass of tanish purple flesh, coated in small barbs and tendrils. It is only as strong as the creatures that make it up, however. If you can manage to kill a decent number of them it should become possible to damage itself, and it can also be killed by some hazards destroying the creature's main body, such as fire, electricity, powerful streams of water, acid, and other enemies that happen to get lucky and not be absorbed. It can also be damaged by Pikmin, dealing more damage than attacking one of the creatures making up its body would, although if your Pikmin aren't whistled back soon enough casualties are a certainty. Some appear simply as decoration, being passive. They always seem to have a decent number of Puffmin in them, which can't be killed and don't count towards defeating it, though they also won't attack. They can attack you with Spores in if you're too far away for any other attacks to reach, and will do so using a similar method to the Puffel. Defeating them is rather difficult, especially without casualties, and as such there is an Achievement attached to doing so.