Answer
"The Italian Stallion" is a nickname famously associated with Sylvester Stallone's character, Rocky Balboa, in the "Rocky" film series. Marciano, the renowned heavyweight boxing champion, was known by various nicknames, including "The Brockton Blockbuster" and "The Cincinatti Cobra," which celebrated his hometown and aggressive fighting style. While both individuals are notable figures, "The Italian Stallion" remains exclusively linked to Rocky Balboa, not Marciano.