Neptunium is a hard radioactive metal that comes just after Uranium. Because of this it was named Neptunium as that’s the planet after Uranium. No prizes for where Plutonium gets it name from. It’s mostly produced as a by product of Nuclear energy production or to make heavier elements.
Earwigs are a rather surprising motherly bug, in that they will look after their young up to their second molt. Their wings resemble ears when unfolded, hence the name. They are tied with Neptunium as I felt how they got their name was similarly odd.
Plutonium is probably the most famous post transuranic metal. Its used nuclear fusion and fission explosions and bombs. It’s also had use a medical indicator but this was never developed beyond lab tests that were nonconsensual. Much like Pluto, Micky’s dog, Plutonium is depicted as a dog. In this case my Dog Willow.