KARKAT: I KNOW THE SCORE I KNOW WHAT'S UP. I'M FAMILIAR WITH THIS SORT OF SEMANTIC TRICK. YOU WANT TO FUCK DOWN ON AN ANIME GIRL WITH CERTAIN CHARACTERISTICS OF A RODENT AND EVERYONE'S GOTTA KNOW.
I headcanon this general hairstyle to be popular with monsters who have fur/hair, and/or human allies of monsters following the end of Undertale.
Chara, during their time in the underground, would tie their hair up in space buns to mimic horns, and kept the front bits longer to mimic goat ears during Dreemurr family royal events.
Post-UT Frisk, after starting as Papyrus’ intern of Human/Monster Ambassadorial relations, started doing horn-buns to resemble/represent their mom Toriel (also the Dreemurrs in general).