The Proto-Zoalords unleashed, by Dr. Yamamura, in the Arizona Base in the 2005 series.
The Arizona Incident (also: Professor Yamamura's Insubordination, Professor Yamamura's Rebellion) is the given name of the event in which four of the Proto-Zoalords rebelled against Chronos and attempted to kill the final and lastZoalord, Richard Guyot. The attack took place while he was still being processed and going through the final stages of being optimized while in his optimization tank. Because the Proto-Zoalords possess the same powers and abilities as true Zoalords (though they don't share the Zoalords own unique powers such as controlling gravity or lightning) the attack itself was disastrous for Chronos's Headquarters and caused severe damage to the facility.
Throughout the battle casaulties were catastrophic for Chronos, who lost large numbers of Zoanoid operatives and Hyper-Zoanoids, who were all but powerless to stop the Proto-Zoalords in their tracks. However, they were able to stall them long enough for the Zoalords to take action. Sense the Council of Twelve was present at the time, they were able to overwhelm the Proto-Zoalords and end their threat, almost immediately once they arrived. The Proto-Zoalords were quickly routed and desposed of, proving to be no match for the superior power and number of the Zoalords. Three of the four Proto-Zoalords were killed, along with the mastermind behind the attack, Dr. Shinichiro Yamamura. There was only one sole survivor of the attack, Masaki Murakami, who barely escaped with his life and swore vengeance upon Chronos. He alone took responisibility for their failure and accepted Dr. Yamamura's mission as his own.