Depending on what animals you are looking for, you might find something you like if you look on ebay or Google "Zuni fetish carvings." The carvers are mostly Native Americans, they use diverse materials, including semi precious stone (examples I've purchased include elk antler, lapis, turquoise, and pipestone), and although most of the carvings are of traditionally American animals, they sometimes carve other types, such as elephants, kangaroos, unicorns, etc.
Although the original carvings were empowered and used for assistance with hunting, etc., the ones offered on websites are generally not empowered, so presumably there wouldn't be an energetic conflict in placing one on an altar.