Eugene Edward "Mercury" Morris (born January 5, 1947), is a former American football running back and kick returner. He played for seven years, primarily for the Miami Dolphins in the American Football League, then in the American Football Conference following the 1969 merger with the National Football League.
Morris played in three Super Bowls and was selected to three Pro Bowls. Mercury was nicknamed early on in his career for his quickness when running with the ball.
Morris excelled as both a running back and kick returner. The majority of his playing days were spent with the Miami Dolphins. From 1969 to 1971, he backed up Jim Kiick at halfback and served as the Dolphins' primary kickoff return man. In his rookie year of 1969, Morris had averaged 26.4 yards per kickoff return, leading the AFL in kickoff returns with 43 and in kickoff return yardage with 1136. Both totals would have also led the NFL. His 105-yard return was the longest in the AFL that season, and he was also one of the AFL's leading punt returners that year. In 1970, he missed some time on the field due to a leg injury, but his 6.8 yard per carry average on 60 runs was the highest in the league among players with at least 50 runs.
In 1971, despite being unhappy with his minimal playing time as backup halfback, he helped the Dolphins to their first Super Bowl, Super Bowl VI by leading the American Football Conference (AFC) with a 28.2 yard kickoff return average.
In the 1972 and 1973 seasons Morris earned Super Bowl rings in Super Bowl VII and Super Bowl VIII and was selected for the Pro Bowl in both years. In 1972, Morris shared the halfback position with Kiick, participating in a few less plays than Kiick, but having more carries as a running back. That year he ran for exactly 1,000 yards on 190 carries, becoming with teammate Larry Csonka the first 1,000-yard tandem in NFL history.