Forbidium
From Jenny Everywhere Wiki
Forbidium was a metal. Pythagoras-858 owned a pair of manacles made of forbidium. (PROSE: Lord Thymon and the Department of Problem-Solving)
Behind the scenes
This is an allusion to the mythos of Disney comics, with forbidium being depicted in The Forbidium Money Bin as the hardest substance on Earth in the Prime Universe.
