An alicorn is exactly like a sylvan unicorn, but with a gnarled and twisted horn.
Combat: Alicorns can use three charm person spells per day. These spells are cast at the 11th level. Those failing to make their saving throws will fight to the death to protect the alicorn from harm. Alicorns can walk on air as if it were solid, running through the air or galloping a few inches above bodies of water.
Habitat/Society: Alicorns are identical in habitat and society to sylvan unicorns. This may account for the fact that the two are often mistakenly classed as being of the same race.
Ecology: Alicorns are on good terms with and respect the territories of sylvan unicorns, cunnequines, and faerie unicorns. The alicorn is otherwise identical in ecology to the sylvan unicorn.