My friend MisterEbony and I am a big fan of both Undertale and MLP, but was shocked at there being so little crossovers when we first got into Undertale. Upon further examination..... I found out why. Silly Pinkie Pie and Flowey stuff! Prepare for comic noms!
And here's the sequel in which everyone's favorite wise-cracking skeleton must ensure that one jealous unicorn doesn't destroy the future: /story/306919/starlight-and-sans