Species: mouth creature

A creature whose primary facial feature is a prominent or exaggerated mouth, with few (or no) other features accompanying it.

Naturally, a mouth creature must have an orifice that can be visually identified as a mouth, and some part of the body that can be identified as a "face".

Goo creatures are often depicted as being able to take insertions in arbitrary locations, but this doesn't mean every orifice is a mouth.
Certain species (such as a feral annelid) may have a bodily form that lacks a distinct head, and therefore a distinct "face".
Certain body parts may have a mouth attached (such as nipple mouths), but this alone does not mean the body part is a "face".