Snakeskin is the most common exotic skin used for cowboy boots. See this page for more information.
A popular skin that is used for cowboy boots is lizard. There are a variety of lizard skins available, but the most common is Teju lizard. The scales of this lizard are large and easily manipulated from which to make boots. This skin can be dyed a variety of colors as well. Being “farmed,” Teju lizard boots are less expensive that other less common lizard skins.
Ostrich skins became very popular on cowboy boots because the hides are durable and water-resistant, and the birds are easily “farmed.” There are three types of ostrich skin available for boots: full quill (meaning that the bumps where the feather quill entered the skin of the bird is still present), smooth (where either the quill bump has been removed or is from a part of the bird's hide where quills are smaller and less pronounced), and “ostrich leg.” Ostrich leg boots are made from – you guessed it – the leg of the bird. The skin has an unusual texture and appearance. It looks great on a pair of cowboy boots.
Other types of skins on cowboy boots are available, such as kangaroo and alligator. Kangaroo leather is rather soft, and easily scratched and scuffed. Alligator skins are selected often because the scales of the hide are unusual and look interesting on a pair of boots. Hornback Caiman alligator skin is found more often on cowboy boots because these alligators produce large hides and the 'gators are easily farmed for this purpose. The bootmaker using Caiman alligator skins gets a very good return on his investment, because the costs to produced the skin are reasonable (compared with others) and the mark-up for boots of this skin is high.