Argus Steel is the main, later secondary antagonist (later reforms) in the 17th Pokemon movie, Diancie and the Cocoon of Destruction. He is voiced by Pete Zarustica.
Argus is an expert thief and has a daughter named Millis. Together, they both plan to capture Diancie because of her power to create diamonds, and use said power to make a fortune. At the same time, their rivals, Marilyn Flame and Ninja Riot, are also after Diancie. After a while, Argus and Millis obtained Diancie after witnessing her diamond-creating powers. Diancie escaped, however, and the father-daughter pair chased after it. When Marilyn and Riot showed up, Argus and Millis got into an altercation with them that culminated in a deep pit with shallow water, where Yveltal just happened to be residing. Their fighting subsequently woke up Yveltal, much to Argus' shock. When Millis was attacked by Yveltal's Oblivion Wing, Argus stepped in to protect her, and wound up getting turned to stone himself. After being healed by Xerneas, Argus abandoned his criminal lifestyle and opened a chocolate shop.
- Argus is obsessed with chocolates, much to Millis' annoyance.
- Despite his thieving ways, he is very protective of his daughter Millis, as shown in the climax.
- Argus has three known Pokemon: Honedge, Doublade and Aegislash.