YTP is a tall, slender monster. He is surrounded by a black mist, which covers his arms, legs, torso, and face. The only parts that are actually visible are the arms, feet, and eyes. His arms and legs appear to be striped, the colors being white and red. He has three, long, protruding fingers branching off of his arm, and 5 toes. His eyes change color.
His eyes can have a total of ten different colors, and they change roughly every 30 minutes. Whenever the colors of his eyes change, his mood drastically shifts as well. However, he still retains his memory.
Here are the colors, and the mood they correspond to:
- Red: While Red, YTP becomes very angry and rage-filled. He will attempt to attack anyone nearby.
- Orange: While Orange, YTP becomes very enthusiastic and adventurous. He loves to explore and meet new people while this color.
- Yellow: While Yellow, YTP becomes extremely happy, as well as motivated and positive. While Yellow, he enjoys giving gifts and being with people he knows.
- Green: While Green, YTP becomes overly enthusiastic about nature and self-harmony. During this, he will usually tend to avoid eating meat and drinking milk.
- Blue: While Blue, YTP will tend to be very calm and relaxed. He can usually be found sleeping on a bench somewhere in Snowdin, or having small talk with people.
- Purple: While Purple, YTP will act highly egotistical and arrogant, usually wearing a cape or robe of some sort. He can usually be found picking on someone or relaxing on a large, cushioned chair.
- Pink: While Pink, YTP will become very flirty, or even very lustful in some cases. He will usually attempt to flirt with anyone and everyone that gets near him. YTP hates this color, but this hate vanishes in his pink form.
- White: While White, YTP will become extremely calm, content, and seemingly pure. He never does anything considered "wrong" in this form, and is usually oblivious to sinful things that happen nearby. He directly counters Pink.
- Grey: While Grey, YTP becomes highly apathetic. When something happens that triggers an extremely emotional response in YTP, whilst not in the right color for said emotion, YTP's eyes will immediately turn grey, and he will loose the ability to feel emotion. This period lasts roughly an hour.
- Black/None: While it appears that YTP actually does not have eyes in this form, his eyes glow a very dark black. During this time, he only feels a genocidal rage, as well as hate. The only possible way to trigger this emotion is to cause an extreme amount of negative emotion to YTP- This can be achieved by doing a genocide route. After roughly 3 days, he will revert to Grey for roughly 6 hour, before finally resuming the normal cycle.