Horses, although this leather is typically found in France and parts of Belgium. It's favoured by Motorcycle GP riders, for it's light weight and durability.
In many ways, Horse Leather is similar to Kangaroo Leather, although not as dry, that's gaining popularity for Motorcycle clothing. Kangaroo Leather was principally used 'Hair-on' for making replica Koala Bear stuffed toys, popular during the 1960's, as the fur is softer than real Koala fur (which is like wire).
Other animals used for leather include Deer and Goats (especially the Chamois). These produce a very soft leather favoured for clothing, usually for women and children.
Bison Leather, was extensively used by Indigenous North Americans for home building, as this leather has a waxy feel, rendering it waterproof.