What term describes a rendered image of a person in which certain striking characteristics are exaggerated in order to create a comic or grotesque effect?

Caricature

The word comes from the Italian 'caricare,' which means 'to load' or 'to exaggerate.' While often used for political satire, Leonardo da Vinci was actually one of the earliest famous artists to sketch 'grotesque heads' that paved the way for the modern caricature.