Not much is known about purple rays. These beams take the form of purple streams of particles, and can be produced artificially. When one is exposed to absurdly dangerous levels of purple rays, the recipient will undergo a temporary mutation whenever they experience sufficient levels of aggravation. To be cured of this condition, the recipient needs to go forty-eight hours without undergoing a mutation so the purple rays can wear off.
Having read the Clunk comic book, which told the fictional story about how Bruce Bandicoot got mutated into the powerful Clunk after being exposed to purple rays, Dr. Eggman made a device for radiating himself with purple rays so he could get superpowers too. Unfortunately for Eggman, all the rays did was give him a condition that turned him into a cuddly creature whenever he got angry. Eggman thus spent the next several days trying to make the purple rays wear off by staying calm.