After a search, it seems to be rare. I did find one that sold on worthpoint in 2017 for $20. But aside from that there's no trace of it anywhere on any marketplace. Probably a ltd ed. tee being stashed away by bronies. here's better images of it to help with your search. I remember seeing this ...

Hi guys. I am working on collecting t shirts from the show My Little Pony Friendship is Magic (2010-2019), specifically the ones with my favorite characters on them. I was wondering if any of you guys are current or former fans of the show (they're called bronies and pegasisters) since you might be ...