My own version of the MLP/Undertale crossover, only the monsters are less pony like.  
Not that the other versions have anything wrong with them but I’d prefer to see a greater variety of monster designs, after all the MLP universe does not lack of them :)
 
I thought that Frisk being a unicorn will open many more possibilities for them. Toriel and Asgore are centaur-like taking inspiration from Tirek. Sans as a dragon because it just makes sense for me and Papyrus as well because they are siblings. Undyne is a sea monster but with stubby legs to walk on land… like an otter! Very little change to Alphys, just have her dinosaur-like. Mettaton is a glorious pegasus.
 
Napstablook- and Flowey will stay the same because they are perfect with the way they are.
 
As for the name of the AU, I was thinking Undertrot (because underequestria and other names are already taken)
 
Sorry for the messy image, I wanted to get this out of my head asap ;w;  
Please note that all characters are not drawn to scale!  
Comment what you think if you’d like. Let me know if the idea is good or should I add or change something.