I also either read about or had a friend say she wanted to do this: If you don't want to do the horn, going for being a purely human representation, for example, you could always have a horn-esque wand, which totally works for the magic the horn represents!
METROlifeMetrocon - Chess: 2006-08; Masquerade 2006-12; Whose Line Host 2005-11; Interactive panel performer: 2008-12; 2009-14 Panel Coordinator, 2012-13 Fantasy Masquerade AD
D*CFriday: Tyleet (ElfQuest), Scootaloo (MLP), Eilonwy (Disney Apocalypse); Saturday: Percy Weasley (Harry Potter), Molly Grue (The Last Unicorn), Big Sister (Battle Royale); Sunday: Fawn (Disney Fairies), Charlie Weasley (HP), ?? (Yule Ball and/or Mechanical Masquerade); Monday: Melody Munns (The Rithmatist)