Demographic category, containing alicorn ponies. Be aware that if you make your character an alicorn, it's very likely to be ignored, especially by main characters.
Alicorns are ponies that have characteristics of all three species of ponies. They have a unicorn horn and pegasus wings with Earth pony characteristics in them. Only four are known to exist in Equestria: Princess Celestia, Princess Luna, Princess Cadence, and Twilight Sparkle.