(Alternate definition)
From TVTROPES:
âWith the release of Chapter 2, the fandom has noticed a pattern where Toby Fox includes a character who happens to be Tall, Dark, and Handsome compared to the rest of the cast (Mettaton, Rouxls Kaard, Swatch), but the fandom always lusts after the short, memetic, superboss instead (Sans, Jevil, Spamton).â
âWhy is everyone lusting after that guy? This guy's so much hotter?â
âToby Fox effect.â