Nihonium gets its name from Japan (Nihon) as the naming rights went to the Riken institute in Wakō. It’s a transactinide that has a very short half life of about 10 seconds. It’s isotopes however are slightly more stable and have contributed to the “Island of stability” theory.
Squirrel gliders are a Australian animal, and as much as I wanted to find a Japanese native animal that was as flighty and unpredictable as a squirrel glider I struggled and eventually ended up tying them to Nihonium.
Flerovium is also a heavy transactinide that sits in the Carbon group of elements. It has had a number of chemical experiments that have shown it behaving somewhat like a liquid or gas, rather than a solid.
Giant Tube Worms are much like other Tube Worms only giant. They are actually fairly small creatures comparatively that live under the ocean near volcanic vents. They build up their Tubes over time and may even pass them onto their offspring. They are tied to Flerovium as they live in heavy liquid.