Greene is credited with providing the foundation upon which Steelers coach Chuck Noll turned the dismal franchise into a sports dynasty.

Throughout his career, Greene was one of the most dominant defensive players in the NFL, able to overpower opposing offensive linemen with ease and disrupt blocking.

Coca-Cola commercial, which aired during Super Bowl XIV and solidified his reputation as a "tough football player who's a nice guy".

[2] In his junior season Greene married Agnes Craft, also a student at North Texas State and the daughter of a Dallas businessman.

[3] As a senior, Greene was a consensus pick as a defensive tackle for the 1968 All-America team, earning first-team honors from United Press International (UPI), the Newspaper Enterprise Association, and The Sporting News, among others.

Two possible origins of the nickname are two separate cheers that supposedly developed independently during North Texas' 1966 game against UTEP.

"[9] Bill Mercer, former North Texas play-by-play announcer, states Graham's thought behind the nickname was the Mean Green defense.

[10] Meanwhile, in the student section, North Texas basketball players Willie Davis and Ira Daniels, unsatisfied with the unenthusiastic crowd, began to sing, "Mean Green, you look so good to me".

"[9] Although it stuck with him throughout his professional career due to his playing style, Greene himself was not fond of the nickname, insisting it did not reflect his true character.

"[12] The Pittsburgh Steelers franchise was one of the most downtrodden in the NFL, having experienced many losing seasons before the hiring of Chuck Noll as head coach in 1969.

[13] Noll and the Rooney family, which had owned the franchise since its formation, agreed that building the defensive line was crucial to rebuilding the team.

The selection proved unpopular with fans and media, who were hoping for a player that would generate excitement; the relatively unknown Greene did not appear to meet their expectations.

[18] Ken Kortas, who had played in all 42 games as defensive tackle over the previous three seasons, was soon traded away to the Chicago Bears to accommodate him on the roster.

Despite his team finishing 1969 with a 1–13 record, the Associated Press (AP) named Greene the NFL Defensive Rookie of the Year,[20][21] and he was invited to his first Pro Bowl.

During the season, Greene tallied 11 quarterback sacks and 42 solo tackles, and he was recognized as the AP NFL Defensive Player of the Year.

[28] Greene was invited to the Pro Bowl for 1973, joining White and Greenwood on the American Football Conference (AFC) roster.

[30] That year, he developed a new tactic of lining up at a sharp angle between the guard and center to disrupt the opposition's blocking assignments.

It proved to be highly effective, as it impeded Buffalo's blocking, and running back O. J. Simpson managed only 48 yards rushing.

[23] The following week, the Steelers faced the Oakland Raiders in the AFC championship game, with the defining match-up being Greene against All-Pro center Jim Otto.

Later, on a third-down play, Greene threw Otto to the ground with one arm before leaping to sack quarterback Ken Stabler.

[39] By 1977, Greene was the captain of the Steelers defense, although his reduced effectiveness over the previous two seasons due to injuries led to rumors that he was washed up.

The Steelers defense allowed a league-low 195 points during the season, en route to a 35–31 victory over the Cowboys in Super Bowl XIII.

In the AFC championship game against the Houston Oilers, the Steelers held NFL MVP Earl Campbell to just 15 rushing yards on 17 carries.

With victory already assured for the Oilers, Greene pointed angrily across the line of scrimmage at Houston quarterback Dan Pastorini, warning, "If you come into the end zone, I'll beat the crap out of you!

[47][53] He also punched Denver Broncos guard Paul Howard and spat at quarterback Fran Tarkenton,[42] and he frequently clashed with officials.

[16] Joe Gordon of the Steelers front office recalled an instance in which a teammate was loudly voicing his discontent over the long and cold practice they had just gone through as he yanked off his equipment.

[42] Greene appeared in a famous commercial for Coca-Cola that debuted on October 1, 1979, and was aired during Super Bowl XIV on January 20, 1980.

[56][57] The commercial helped shift the public's perception of Greene as hostile and unapproachable, to a soft-hearted "nice guy".

One of his first acting roles was in The Black Six, a blaxploitation film starring other NFL players including fellow Hall of Famers Lem Barney, Willie Lanier, and Carl Eller.

[58] Greene also played himself in the movie ...All The Marbles, a TV movie on teammate Rocky Bleier, titled Fighting Back: The Rocky Bleier Story, and in Smokey and the Bandit II, in which he was ordered to "tackle that car" by Terry Bradshaw when Sherriff Buford T. Justice, played by Jackie Gleason, was in pursuit of Burt Reynolds' "Bandit".