At 6 feet 10 inches (2.08 metres) tall, Johnson was the tallest player in MLB history when he entered the league, contributing to his extremely intimidating persona and pitching style.

On May 18, 2004, at 40 years old, he threw Major League Baseball's 17th perfect game, and remains the oldest pitcher to accomplish the feat.

[7] He made his major league debut on September 15, 1988, against the Pittsburgh Pirates, earning a 9–4 victory with a five-inning outing in which he gave up two runs with five strikeouts; his first victim was Orestes Destrade in the second inning.

His untapped talent was explosive: In 1990, Johnson became the first left-hander to strike out Wade Boggs three times in one game, and a no-hitter against the Detroit Tigers attested to his potential.

Prior to the trade deadline, Johnson was nearly dealt to the Toronto Blue Jays for Steve Karsay and Mike Timlin.

[12] At the 1993 All-Star Game in Baltimore, Maryland, in a famous incident, Johnson threw a fastball over the head of Philadelphia Phillies first baseman John Kruk.

[13] On October 3, Johnson entered the final game of the season as a defensive substitution, replacing Brian Turang in left field.

[14] After pitching well in the strike-shortened 1994 season, Johnson won the American League Cy Young Award in 1995 with an 18–2 record, 2.48 ERA and 294 strikeouts.

Johnson capped the Mariners' late-season comeback by pitching a three-hitter in the AL West's one-game playoff, crushing the California Angels' hopes with 12 strikeouts.

[15][16] Another colorful All-Star Game moment proceeded in the 1997 edition involving former Expos teammate Larry Walker, at that point with the Colorado Rockies.

[17] When Johnson had started an interleague game versus the Rockies on June 12, Walker chose not to play, explaining that "I faced Randy one time in spring training and he almost killed me.

Ever adaptable, Walker placed his batting helmet backwards and switched sides in the batters' box to stand right-handed for one pitch.

[19] The incident momentarily drew mirth and laughter from players in both dugouts, fans and announcers, and, of course, comparisons to the at bat with Kruk in the 1993 All-Star Game.

[24] Though the Mariners initially wanted to keep Johnson, turning down a trade offer from the Los Angeles Dodgers,[25] they fell out of contention, going 8–20 in June.

[30] In the fourth year of the franchise's existence, Johnson and Schilling carried the Arizona Diamondbacks to their first World Series appearance and victory in 2001 against the New York Yankees.

[34] In a freak accident on March 24, 2001, at Tucson Electric Park, during the 7th inning of a spring training game against the San Francisco Giants, Johnson threw a fastball to Calvin Murray that struck and killed a dove.

In 2002, Johnson won the pitching Triple Crown, leading the NL in wins, ERA, and strikeouts, and was voted his fourth consecutive Cy Young and Warren Spahn Awards.

He also became the fifth pitcher in Major League history to throw both a no-hitter and a perfect game in his career (after Young, Bunning, Addie Joss, and Sandy Koufax; since Johnson, Mark Buehrle and Roy Halladay have joined this group).

Johnson struck out Jeff Cirillo of the San Diego Padres on June 29, 2004, to become only the fourth MLB player to reach 4,000 strikeouts in a career.

The Diamondbacks traded Johnson to the New York Yankees for Javier Vázquez, Brad Halsey, Dioner Navarro, and cash in January 2005.

Johnson did not make the original edition, but for the 2005 update, with his career totals considerably higher and his 2001 World Championship season taken into account, he was ranked at Number 60.

In Game 5 in Anaheim, Johnson made an effective relief appearance with 4 1/3 scoreless innings after Mike Mussina gave up 5 runs and 6 hits to give the Angels a 5–2 lead, but the Yankees were unable to come back in the series.

After being given epidural anesthesia and a few bullpen sessions he was cleared to start in game 3 of the ALDS; however, he gave up 5 runs in 52⁄3 innings and being saddled with the loss.

[49] Johnson made his season debut on April 14, 2008, against the San Francisco Giants at AT&T Park eight months following his back surgery.

[60] At age 46, he was at the time the second oldest player in Major League Baseball, trailing only former Mariners teammate Jamie Moyer.

[67] At the retirement ceremony, Johnson was presented with a replica of the drum set used by Neil Peart, drummer for the Canadian band Rush, during their 30th anniversary tour.

The effectiveness of the pitch is marked by its velocity being in the low 90s along with tight late break; hitters often believed they were thrown a fastball until the ball broke just before it crossed home plate.

[86][87] During batting practice in 1988, the 6-foot-10-inch (2.08 m) Johnson, then with the Montreal Expos, collided head-first with outfielder Tim Raines, prompting his teammate to exclaim, "Damn!

After his retirement, the title of tallest player was held by Johnson's former Diamondback teammate Jon Rauch, a relief pitcher who is 6 feet 11 inches (2.11 m).

The spots comedically portrayed him taking batting practice (swinging ineptly at balls from a pitching machine) in his hope that he would break Roger Maris's then-single-season record for home runs.