Just in case anyone not familiar with Monster Hunter ever sees this and is confused about the "antennae" and "fake horns" tags, Gore Magala has no eyes, and the things that look like horns are actually the feelers it uses to sense its surroundings, which are prehensile and retractable.
So, while they're not "fake horns" in the sense of being horns attached to an accessory worn by a character, they are "fake horns" in the sense that they are shaped like horns but are not actually horns. They harden and become true horns when it molts into Shagaru Magala and gains eyes.