Help me find that image source/artist

Can’t figure out who the artist is. I don’t recognize the signature. Reverse search spits nada. I asked the fellow who posted it and he doesn’t know either.  

 
Also straightpip best Pip

Artist tag is PonyNamedMixtape

@IvanSatoru  
Howdy there. Yeah that’s my stuff. Commissioned by a buddy of mine. Glad you like it!
 
Most of my stuff here is imported from derpi cause I’m not that active on Ponybooru. I also don’t have a Twitter anymore so you can really only findy stuff on the boorus.

@TheMixtapeHorse  
It’s very cute and I love it. You and your pal are incredibly and wholesomely based.

@Ponkus  
And thank you too