Surprise! :D I bet that many of you weren't expecting to see artwork from me.

Nothing fancy or spectacular. Just a pencil doodle of what this kiddo might look like in Gravity Falls style.
NOTE: This is just a practice doodle as I am in the process of learning how to draw. I followed step-by-step instructions on how to draw Mabel Pines and I just added some of my own modifications to it as I drew.
Not trying to pat myself on the back or anything, but I would say that this is "pretty good" for a first attempt. I actually drew Mabel herself for practice before attempting to draw Frisk.

In addition to Undertale, I am also a huge fan of Gravity Falls and I often think about what an Undertale/Gravity Falls crossover would be like. Speaking of that, I might (strong emphasis on "might") write an Undertale/Gravity Falls crossover story at some point. I'm thinking that I would have it take place between "Roadside Attraction" and "Dipper and Mabel vs. the Future." My setting would be that Frisk and Asriel are on vacation with Sans and Papyrus and the four of them just happen to stumble upon the town of Gravity Falls, Oregon and meet our favorite Mystery Twins. :)

Frisk and Undertale© Toby Fox.
Gravity Falls© Alex Hirsch and Disney