Rolling forward mebbe we ought to confine our description of motormouth to PORCINE SWINE. In deference to pigs who are benign. You on board?

PORCINE
Of or pertaining to swine; resembling swine, hoggish, piggish

SWINE
Coarse gross brutishly sensual
A contemptible person

If the shoe fits. Well what better fit than that is there for the motormouth? Porcine swine.