These are the 3D unicorn horn panties handmade by Etsy seller knickerocker (previously: their cupcake and other animal face undies). They cost $45 a pair (for reference, I've never spent more than $1 for two pairs of underwear at a garage sale), and are accentuated by a soft, plush horn. Obviously, they're for frolicking around the bedroom like the sexy, mythical beastess that you are and not to be worn under jeans unless you want to look like you just shit your pants, which isn't a good look for anyone. Trust me -- that was my look for a long time. "Was?" Hasn't happened today!
UPDATE: Happened today. :(
Keep going for a couple more shots, including two with significantly less butt while I call my mom to see if she can bring me a change of clothes to school.
Thanks to Christina D, who agrees now it just needs to shoot rainbows/laser beams on command.