Exovoviviparans are a clade of animals roughly as broad as Earth mammals. They're known for reproducing via womb nests, hence the name. They also bear fur, although they're not the only animals to do so. Yinrih and tree dwellers are members of this clade.

Other exemplars are forest flyers (small flying animals that look like a cross between a bat and a colugo). These were one of the first animals domesticated by the yinrih, being favored for eating pests. In modern times they're kept as house pets, occupying a similar cultural niche as cats do for humans. The Commonthroat word for forest flyer <sMPrg> /yip, long rising strong grunt, chuff, short low weak growl/ can also mean a person who appears clever without actually being clever.