Phillip

Philip is the twin brother of Pixie, Bailey's horse while she's there and is known to have bare the king of Narnia, Edmund Pevensie.

Movie adventures I: Narnia
Philip first appears when Edmund and Peter are playing together riding their horses, which Edmund calls him a "horsey" before, Philip tells him what his real name was. Philip later was ridden by Edmund right after Bailey Morris and her sister Lauren went to the next world.