Rubicon was a WRB bot. He won against Noisy Boy for WRB championship in the year 2016. Max said that Rubicon won in the third round when he got lucky and knocked out Noisy Boy. He also defeated the very first WRB champion, Gamma. He was made in Russia (just like Zeus) and was destroyed by a different bot to lose his championship, as he was champion for years and years before Zeus.
Rubicon has never made an appearance in Real Steel the movie and the games.