Mud

Mud is an environmental hazard taking the form of wet earth. It consists of large pools and can be frozen. Shallow mud can be traversed by all Pikmin types and leaders, though wading through it naturally reduces their speed, and deep mud will cause leaders, and Pikmin that can't float on the surface or fly above it to drown. Some enemies can use mud offensively, and others can submerse themselves in it.

=In fanon games=

Pikmin V
Shallow and deep mud appear in Pikmin V, though deep mud is depicted as especially marshy ground rather than as a pool. They are found predominately in the Sodden Swamp area and its cave, Bog Network. Orange Pikmin are not slowed by and do not sink in mud, and the lack of Ice Pikmin to freeze it makes them, along with Winged Pikmin, the only means of traversing the hazard. Quicksand is a functional variant of deep mud.