Tardigrades are the most resilient beings known to humans, Wiki: 'with individual species able to survive extreme conditions—such as exposure to extreme temperatures, extreme pressures (both high and low), air deprivation, radiation, dehydration, and starvation—that would quickly kill most other known forms of life. Tardigrades have survived exposure to outer space.' Wiki: 'Tardigrades are thought to be able to survive even complete global mass extinction events due to astrophysical events, such as gamma-ray bursts, or large meteorite impacts.' Basically Tardigrades forgot how dying works, they can last 30 days without food or water when in 'survival mode' and can last 10 days in space, needless to say, a creature based on Tardigrades would be pretty cool just look up tardigrades they even look like monsters
https://en.wikipedia.org/wiki/Tardigrade If you need a suggestion on where to put these little things I say nature or gravity.