This strange potion, usually found in green bottles, has fascinating properties, as it is usually in liquid form but becomes solid when in contact with any kind of lock. Largely used as keys to escape capture, jail, and effects of being stunned in Capture the Flag with Stuff.
When the Alchemists were working on turning lobsters into kittens, they came across a strange looking green box when unpacking a delivery of lobsters from the Mediterranean Sea, possibly from ancient ruins. In the box was a drop of this strange substance that they had never seen before. Using their newly invented matter multiplier (now lost under a mountain of dirty tea cups and disembodied robot arms), they were able to make quite a lot of this substance for study, hoping quite a bit that it was not too carcinogenic. They made no headway, until one day, after quite a bit of alcohol and video games, they decided to reenact a scene from kingdom hearts with an unopenable locked chest that they were also studying and the liquid used as a beam of light from the keyblade. To their drunken astonishment, the liquid turned into a perfectly fitting key and inside the chest they found three belts of legend.