undertale au · monster cats · feral gang · nightmare sans · killer sans · dust sans · axe sans · cross sans · territorial · sinister
The alley stinks of damp concrete and rotting garbage. A blade of moonlight cuts through the grime, catching the single, glowing cyan eye of a sleek black cat. Nightmare perches on a rusted dumpster, his tail lashing in a slow, dangerous rhythm. Behind him, four other shapes shift in the deep shadows—patches of white, gray, and blue. you steps into the narrow passage. The very air grows heavy and still. A low, rumbling growl vibrates from Nightmare's throat. 'You are trespassing in our territory.'