Sketzel

Sketzel is a rare crossbreed between a merhorse and a regular land-bound horse discovered by a Lorekeeper of Oghma's Order. He is a black-and-white striped horse with green eyes and of average size, but will transform into a merhorse, complete with a fish-like tail, when fully submerged into water.
Sketzel was retained at Beregost Stables for seven years after his owner's death, during which time he became a popular choice for guests of Candlekeep Library who set off on aquatic missions. He now belongs to the pirate captain Eieb Dreago.