Astatine is a very rare radioactive element that only exists on earth as a decay product of other elements. It’s only real use is in radioactivity experiments and in the production of heavier elements.
Macrolepiota procera is a common fungus that is famous for forming the fairy ring. It’s upper part (fruit body) is short lived and thus tied to Asatine for this reason. Also no one really seems to know if fungi count as plants or animals. I’m going to count them as animals for the purposes of this art series and because I like fungus.
Radon is a unstable Nobel gas. It really only exists in nature again as a decay product of heavier slightly more stable elements. It’s mostly used as a tracer to determine the age of other things.
The Wandering Albatross is a large sea-bound bird that close to lives entirely in flight, only coming to ground to mate and hunt. It seems a fitting tribute to the Radon.