Look what info I found!
Chimera Mutagen
While I don't have any specimens with me, I do have the formula for the mutagen...
The chimera mutagen, Galactic Plasma's greatest weapon, allowed humans to combine their DNA with that of up to 3 Pokémon, and become a hybrid. However, the change is permanent, and cannot be reversed. In the Orre Region, after GP's fall, a tyrant group called "Black Alpha" used chimera mutagens of Crappy Pokémon combinations, like Slakoth/Slowpoke/Jynx as a weapon, while using things like Garchomp/Porygon-Z/Mienshao for themselves.