In the last few months of Project Loco, the government was getting less enthusiastic about Doc's creations. With limited to no success with integrating them into the public, the gov gave Doc 3 more chances to prove his Locomatons can in fact be life like. So, Doc made the last 3, none of which successful.
The final strike is simply called Cauldron.
As Doc's last chance to prove locomatons' worth, Cauldron had to be perfect. And perfect he was. He was a polite, nice, charming lad who did what he was told. He was given to a wealthy oil tycoon as a sort of butler. Everything seemed fine until he unintentionally received some bad moral advice when the tycoon crushed an ant. "It is merely one small insignificant life-form. It doesn't help out the world anyway, so it won't be missed." he said. Actually believing these words, Cauldron went and killed a rabid dog that has been causing the trouble, believing it as insignificant. The matter worsened when he decided to slaughter a parolee . Cauldron's mindset became "He himself is significant, everything and everyone else isn't." He was arrested and declared to dangerous, and was locked away for good.
With Cauldron behind bars, the gov decided to not take any more chances and shut down Doc's Loco project.