The Mr. Hyde Formula is a purple liquid in a glass vial.
The formula was crafted from alien blood by Dr. Jekyll for the Forever Knights for use in battle.
Wes Green found vials containing the formula, but destroyed them once he learned of its true nature, with the one remaining vial being used by Forever King Chadwick, turning him into a gorilla-like alien hybrid.
Ben 10: Omniverse
- An American Benwolf in London (first appearance)