Josip Hrvoje Peruzović (October 14, 1947 – July 29, 2018), better known by his ring name Nikolai Volkoff, was a Croatian-American professional wrestler, best known for his time in the World Wrestling Federation (WWF).

In the 1970s, Peruzović was Bepo Mongol of the Mongols tag team with Geeto Mongol, and one of the masked Executioners. He later transitioned to singles competition as Volkoff, a Russian Soviet heel, and feuded with Bruno Sammartino over the WWWF World Heavyweight Championship. In the 1980s, he tag teamed with the Iron Sheik and won the WWF Tag Team Championship at the inaugural WrestleMania event.

In 1990, Volkoff turned face and defected to America, briefly feuding with Zhukov and newly-heel Iraqi sympathizer Sgt. Slaughter. In 1994, after a hiatus, he returned as a destitute and desperate character, exploited by Ted DiBiase as the first member of his Million Dollar Corporation. He continued to wrestle in various promotions until his death in 2018.

Peruzović grew up in the Socialist Republic of Croatia, which was then part of Yugoslavia, to ethnic Croat parents Ivan and Dragica Peruzović (nee Tomašević). His maternal grandfather Ante Tomašević, originally from Sinj, was world champion in the Greco-Roman wrestling style at the turn of the 20th century. According to Freddie Blassie's autobiography, Peruzović's family also had Russian and Italian ancestry.

Peruzović would claim in later life that "Volkoff" (Russian: Волков) was a surname from his mother's lineage. He would also claim that "Nikolai" was his middle name, which was false, his actual middle name was Hrvoje.

He was on the Yugoslavian weightlifting team until 1967, when he emigrated to Canada after a weightlifting tournament in Vienna, Austria. He received training in Calgary from Stu Hart, followed by his arrival in the United States in 1970. A fellow Croatian-native played the first Soviet Volkoff character in American pro-wrestling. Steve Gobb (originally Gobrokovich) wrestled as USSR's Nicoli [sic] Volkoff in the 1960s before the character was picked up by Peruzović.

While trying his luck as a wrestler in Calgary, Alberta, in 1967, he met wrestler Newton Tattrie, who was wrestling for Stu Hart's Stampede Wrestling. During his 1963–1968 tour, Tattrie took Peruzović under his wing as a protégé and trained the non-English speaking, 315-pound man to become a professional wrestler and tag team partner. When Tattrie left the territory in 1968 for the US, Peruzović left with him, working in various territories for the National Wrestling Alliance including NWA Detroit, the International Wrestling Association and the National Wrestling Federation where they won tag gold.

In 1970 he began wrestling in Vince McMahon Sr.'s World Wide Wrestling Federation (WWWF) (currently known as WWE). Wrestling as Bepo Mongol, managed by "Captain" Lou Albano and partnered with Newton Tattrie (as Geeto Mongol) as the Mongols billed from Mongolia. They captured the WWF International Tag Team Championship from Tony Marino and Victor Rivera on June 15, 1970. After losing the title to Luke Graham and Tarzan Tyler in a match over a year later that unified the WWWF International and WWWF World Tag Team Championship, Peruzović left the WWWF and went on to singles competition under the name "Nikolai Volkoff".