Plutonium

Plutonium is an element used heavily in the show.
==In the show==
Plutonium is the only known element able to cut through Batfink's wings. It is used by many criminals, and even a candy-factory because of it's hardness.
It is also radioactive, and gave Batfink the source of his strength as he was raised in a plutonium mine.
The element is also able to be made into other matierials, such as glass.
==In Reality==
See this link  and that linkfor more info.
It is extremely radioactive and used to make nuclear weapons. It is mostly man-made, and rarely ever seen in nature.
It is highly illegal to own today (unless you work at a nuclear plant), although during the 1950's it was considered extremely safe, as most nuclear matierials were during the 50's, since the harmful effects of radiation were unknown at the time. It was once used in pace-makers.