Tardigrade https://kids.nationalgeographic.com/animals/invertebrates/facts/tardigrade
You can boil them, bake them, deep-freeze them, crush them, dehydrate them, or even blast them into space. It doesn’t matter—tardigrades can survive practically anything. These eight-legged aquatic animals may be small, but they’re nearly indestructible.
Nematodes (a kind of worm), amoebas, and sometimes even other tardigrades all prey