Randall David Johnson , nicknamed "the Big Unit", is a left-handed American starting pitcher who currently plays for Major League Baseball's Arizona Diamondbacks.

The 6-foot-10 Johnson has been celebrated for having one of the most dominant fastballs in the game. He regularly approached, and occasionally exceeded, 100 miles per hour during his prime. However, his signature pitch is a hard, biting slider. Johnson has won the Cy Young Award five times, second only to Roger Clemens' seven.