Equus

Equus aims to expand both the utility and adventure surrounding horses in minecraft.
Eventually, the mod will add multiple rare horse subtypes, one for each dimension, each of which will have unique abilities to help traverse areas.

For now, the mod adds:

Posian horses – Rare horses found on the surface of deep ocean biomes. These horses are able to run on water and cannot drown. They are tamed using prismarine shards and crystals, or the new aqueous carrot item, which is also used to breed them.

Hadean horses – Rare horses found in the clutches of the nether. This horse variety typically comes equipped with horns as opposed to standard fur patterns, helping to scare off many common hostile mobs. They are tamed using blaze rods or powder, magma cream or the new infernal carrot item, which is also used to breed them.

Recipes for saddles and existing horse armor.