Adult Content Warning

This work could have adult content. If you continue, you have agreed that you are willing to see such content.

• Yes, Continue
• No, Go Back

If you accept cookies from our site and you choose "Yes, Continue", you will not be asked again during this session (that is, until you close your browser). If you log in you can store your preference and never be asked again.

1. The Man In Monochrome by Thirsty Individual (Biggest_Spider_Alive)

   Fandoms: Undertale (Video Game)  

   • Not Rated
   • Creator Chose Not To Use Archive Warnings
   • No category
   • Work in Progress

   05 Jul 2026

   Tags

   • Creator Chose Not To Use Archive Warnings
   • W. D. Gaster/Reader
   • Alphys/Undyne (Undertale)
   • Mettaton/Papyrus (Undertale)
   • Alphys (Undertale)
   • Toriel (Undertale)
   • Frisk (Undertale)
   • Sans (Undertale)
   • Gaster Follower(s) (Undertale)
   • Undyne (Undertale)
   • Mettaton (Undertale)
   • Post-Undertale Pacifist Route
   • Selectively Mute Frisk (Undertale)
   • Reader Is Not Frisk (Undertale)
   • Gender-Neutral Reader-Insert
   • Scientist W. D. Gaster
   • Scientist Reader-Insert
   • Slow to Update
   • Canon-Typical Racism
   • Warning: Weezer
   • Echo Flowers (Undertale)
   • Minor Original Character(s)
   • Alternate Universe - Canon Divergence
   • Big Brother W. D. Gaster
   • Cosmic Horror
   • Lovecraftian Cults
   • Touch-Starved
   • Reader-Insert Has PTSD - Post-Traumatic Stress Disorder
   • Depressed Reader-Insert
   • reader has light celebrity crush on Mettaton
   • Suicidal Thoughts

   Summary

   Monsters reemerging from Mt. Ebott shocked the world. The thing that shocked you was being invited to work as a researcher in their labs. As you explore your new home, you attract the attention of someone very, very interesting.

   Except

   You're not even sure WHAT he is.

   Language:

   English

   Words:

   9,560

   Chapters:

   2/?

   Comments:

   10

   Kudos:

   28

   Bookmarks:

   4

   Hits:

   200