The story
From over- (prefix meaning ‘excessive; excessively’) + egg, from the phrase over-egg the pudding, a reference to adding too many eggs to a pudding and thereby ruining it.
Etymology from Wiktionary, CC BY-SA 4.0.
overegg
over·eggToday it means: Chiefly in over-egg the pudding: to spoil (something) by exaggerating it, or an aspect of it; to overdo. Full definition →