Sleipnir is the eight legged steed of Odin, offspring of Svaðilfari and the trickster god Loki. Svaðilfari and his master were contracted to build the walls of Asgard in three seasons by themselves. If they did, they would get the goddess Freyja, the sun, and the moon. When it looked like they would finish on time, Loki changed himself into a mare and distracted Svaðilfari. Sleipnir was the resulting offspring.

The original mythology is relatively sparse on how exactly Sleipnir's eight legs worked, so I went for making him a conjoined twin. He's fused at chest and head. The inner set of legs is fused from shoulder to knee, then is free from knee to foot. The double foot style is used in some old Icelandic depictions, though give him only 4 legs and a single chest.

The necks are separate at shoulder and then curve back in to fuse into a single head. He has two tails.

Original for sale:
http://www.etsy.com/listing/7638895.....ged-horse-ooak