Spotcap

The Spotcap is the smallest fungus, with varying sizes near those of a leader. If a Pikmin is issued to attack a Spotcap, they'll pummel it for a bit, until it shrivels up and disappears, but if a Pikmin is thrown straight towards its top, it will crush the fungus and delete it straight away. In addition, there is another mushroom similar to the Spotcap that is completely brown, cannot be locked on to, and also disappear if a Pikmin is thrown on top of it. The two function similarly, and while the latter is not given a name, it is assumed to be another form of Spotcap, or at least closely related to it.

Pikmin: Infection in Progress
Spotcaps return yet again in Pikmin: Infection in Progress. Spotcaps appear infrequently in the Polluted Twilight River, Rotting Oak, Toxic Wilds, and the Wilting Garden of Infection. An area in which Spotcaps are incredibly common are The Fungal Forest Navel. Due to the plague spreading across the Distant Planet, mushrooms have spread immensely, especially underground. Destroying a Spotcap will make it shrivel and disappear, very similar to how they did in Pikmin 3.