William Reid Eadie (born December 27, 1947) is an American retired professional wrestler, best known for performing under the ring names The Masked Superstar and Ax, the latter as part of Demolition.

Eadie was born in Brownsville, Pennsylvania in 1947. He attended Brownsville High School, where he competed in gridiron football and track. After graduating high school in 1964, he attended West Virginia University on a track scholarship. After graduating in 1968, he worked as a high school teacher and coach at Cambridge High School in Cambridge, Ohio, and at East Liverpool, Ohio.

While attending a wrestling event in the early-1970s, Eadie met professional wrestler Geto Mongol, who invited him to train as a wrestler. Eadie's first match was on December 15, 1972, under the name "The Paramedic". Throughout 1973, he wrestled under a mask as the tag team "Para-Medics" in the Sheik's Detroit territory.

Eadie then wrestled in Pittsburgh, Detroit, the World Wide Wrestling Federation, and the IWA as "Bolo Mongol", the new partner of Geto Mongol.

In 1976, Eadie entered the Mid-Atlantic Championship Wrestling territory under the management of Boris Malenko and donned a mask as "the Masked Superstar", given the character at the advice of matchmaker George Scott. It was stated that he was an Olympic champion by various wrestling promoters. He challenged opponents with a $10,000 reward to whoever could break his "cobra clutch", as well as utilizing the "corkscrew neckbreaker". The Masked Superstar was 6' 3", weighed 300 lbs and created many mismatches due to his size, strength and quickness. He had many bouts with Mighty Igor, Paul Jones, Blackjack Mulligan, Wahoo McDaniel, Mr. Wrestling II, Stan Hansen, "Wildfire" Tommy Rich, and Dick Murdoch. In 1978, he was the first wrestler (along with Blackjack Mulligan) to have one-hour cage matches, then have a series of "12" ninety-minute cage matches, against Mulligan. It is believed that neither feat of hour or hour and a half cage matches has since been performed by any wrestlers. He was one of the first wrestlers to body slam André the Giant.

From 1978 to 1980, Eadie wrestled for Georgia Championship Wrestling. Among other accomplishments, he won four Georgia Heavyweight titles and unified that title with the NWA National Heavyweight Championship.

Eadie left Georgia in February 1980 and returned to Mid-Atlantic Championship Wrestling as "Masked Superstar" later that month. Shortly after returning, he began teaming with Masked Superstar 2 as the "Masked Superstars". In March 1980, the Masked Superstars defeated Dino Bravo and Ricky Steamboat for the NWA Mid-Atlantic Tag Team Championship; in the same month Eadie defeated Blackjack Mulligan to win the vacant NWA Television Championship. In April 1980, Masked Superstar 2 was unmasked, causing him to leave the territory; the Masked Superstars subsequently vacated the NWA Mid-Atlantic Tag Team Championship. Eadie continued to defend the NWA Television Championship until vacating it in October 1980.

In September 1980, Eadie began teaming with Paul Jones and Ricky Steamboat to repeatedly challenge for the NWA World Tag Team Championship (Mid-Atlantic version). In November 1980, Eadie and Jones finally defeated Jimmy Snuka and Ray Stevens in a cage match to win the titles. Their reign lasted until March 1981, when they lost to Stevens and Ivan Koloff. They regained the titles from Koloff and Stevens later that month, holding them until May 1981 when they were defeated by the Minnesota Wrecking Crew. Later that month, Eadie repeatedly unsuccessfully challenged Roddy Piper for the NWA United States Heavyweight Championship (Mid Atlantic version). Eadie left Mid-Atlantic Championship Wrestling once more in June 1981 for a tour of Japan.