This article is about the adrenaline parasites. For the season 8 character, see Rudy Jones.
The Kawatche Caves contained alien parasites. Analysis at Cadmus Labs showed that their physiology is completely unique and their DNA is not from Earth; along with the history of the Kawatche Caves, this suggests that the parasites may be Kryptonian in origin.
Powers and Abilities
The parasites secrete a substance that causes excessive adrenaline and enlarging of the adrenal glands in its host, causing the host to behave impulsively and act on any latent desires or aspirations. In all but those two cases, the final result was death by suicide. 
Sometime after, Lex's scientist Dr. Brody extracts enzymes from the parasites in hopes of making a profitable discovery with them. Desperate to continue his research, he injects a serum (containing the enzymes) into the lab monkey Lester. 
Lester broke free to and is encountered by Chloe (who he injects with the serum). Soon after, she injects the serum into Lana, resulting on them causing trouble throughout town. Eventually the serum wears off, and they are left with no memory of what happened. 
- The Nicodemus flower, which induces similar effects.