Fell Sans

Nicknamed "Red";
He always wears a spiked collar around his neck, which is a gift from his brother;
The fur on his jacket is golden, and the jacket itself has red stripes. His sleeves also have fur;
Wears a red striped sweater, sometimes depicted with a buttoned jacket;
He doesn't wear a chain around his neck or rings under his gloves, nor the gloves themselves, because he can summon blasters as much and as often as he wants;
The skull is the same as the original, only it is full of cracks and scars;
Has red bags under the eyes;
Has jelly-like internal organs (tongue, etc.);
The color of the bones does not differ from the original;
When at rest, his pupils are red slits/white ovals;
Fights on the Neutral/Pacifist path, where his eye can glow yellow and red, only red, or red and purple;
He often swears and uses obscene gestures, otherwise he is a poor weakling who has been badly battered by life and who is trying with all his might to save Frisk;
Smokes;
He is afraid of his brother and listens to him in everything, so he only calls him boss;
Makes vulgar or black humorous jokes, not knock-knock jokes.