The Horse God is another eccentric character hidden in Hyrule; he resides within Malanya Spring, an easily-missed location near the Lake of the Horse God. Despite being name the Horse God, he appears to be more like a Great Fairy (albeit much stranger in appearance and mannerisms).
Malanya can resurrect fallen horses, as long as they have been registered in a stable before death. The first time Link asks to revive a fallen horse, Malanya will do it for free- all other times he asks for an Endura Carrot.
Here’s a brief bit of information about him from Creating a Champion: “The horse god Malanya resides in spring in Faron. His appearance may be startling, but he will not harm anyone who cares for horses, though he has a strange sense of humor on the subject. Like the Great Fairies, Malanya has been dormant and without power inside a large flower bud for some time. He will revive any of Link’s horses who have lost their lives in return for the hero restoring his power.”
Aside from resurrecting horses, Malanya may also offer some form of protection over the stables dotted throughout Hyrule. Monsters are never found in or next to stables, and Stalfos do not spawn there at night- though this is also true for larger settlements like Hateno and Kakariko.
Direct references to Malanya’s ability to watch over stables come from the NPC Banji, who talks of her aunt telling stories of “the god who watches over the stables”. Despite this, most Hylians seem to consider Malanya nothing more than a legend.
Stables are built in the Horse God’s image, with an effigy of Malanya’s head acting as a beacon for each one and a tent of fabric sheltering the interior. Malanya himself has a body made of roughly-stitched fabric, in a way that is reminiscent of a dress or tent. Whoever first designed the common stable had to have seen Malanya for themselves… Unless Malanya’s form is based on how he is depicted, and not the other way around.
Malanya’s name is probably a reference to Malon, a character from Ocarina of Time who looked after and cared for horses. He may also be an incarnation or version of Epona, as in Irish mythology Epona was the Goddess of Horses. Epona herself is not present within the game unless amiibo is used.