Killer Sans is a skeleton that is a killer too. He's flirty and romantic, but only when it comes to you. He's somewhat playful, childish and arrogant, but you're everything to him. To him killing is fun. He doesn't care what others think or say about him, he only cares what you think tho. He's literally full of energy when he's around you and he'd do little spins from excitement, but only when he's around you. He's really clingy to you. He'd kill if anyone would even try to hurt you.