Brockium is a chemical substance that forces dragons to shapeshift into their dragon form unwillingly. It is featured in the television show American Dragon: Jake Long. It was developed by Sigmund Brock in his attempt to expose magical creatures to the world.
Sigmund Brock, a researcher of the Magical World, entered into a deal with an unknown party. With this party's resources, Sigmund created this substance but he doesn't have a dragon to test it on. After Jake causes Rotwood to be fired, Sigmund becomes Millard Fillmore Middle School's new principal.
He plants magical bugs on the basement, thinking that it will draw the dragon to fight against them. His plan works as Jake, Trixie, and Spud go to the basement to fight them. Brock then brings Jake to his office where he reveals his plan to expose magical creatures.
He later traps them in a jail and pushes them to the auditorium where he plans to use the brockium. However, Rotwood lies to him telling that Spud is really the dragon. Sigmund uses the vial on Spud, who obviously doesn't shapeshift, making Brock look like insane.
A drop of the vial, however, remains and Rotwood uses it to shapeshift Jake's hand, thus proving the chemical works as Rotwood was proud of himself because this proved his theory about Jake being a dragon.