Defilement: Ceremonial Caused by Touching a Dead Beast
Source: TTT
Leviticus 5:2
Or if a person touches anything unclean—whether the carcass of any unclean wild animal or livestock or crawling creature—even if he is unaware of it, he is unclean and guilty.
Leviticus 11:24–28
These creatures will make you unclean. Whoever touches their carcasses will be unclean until evening, / and whoever picks up one of their carcasses must wash his clothes, and he will be unclean until evening. / Every animal with hooves not completely divided or that does not chew the cud is unclean for you. Whoever touches any of them will be unclean.