For those not in the know: the text, pose, and purple aura here are a reference to the final battle against Dr. Andonuts in Toby Fox's "Halloween Hack" of Earthbound/Mother 2, which is best known as the origin of the "Megalovania" song that was later remastered for use in the Sans fight in Undertale. "tl;dr: eat shit, faggots" is the final line Dr. Andonuts says before the fight proper starts, and if you're reading his pre-fight monologue at a reasonable pace (as opposed to just button mashing to skip the text or lingering on it overly long), Megalovania will begin playing at roughly the same moment as this line drops.
