Which Looney Tunes character is a turtle who once beat Bugs Bunny in a race?

The Looney Tunes character who is a turtle and once beat Bugs Bunny in a race is Cecil Turtle.

Cecil debuted in Tex Avery’s 1941 short Tortoise Beats Hare. Bugs, confident that speed will guarantee victory, challenges Cecil to a ten-dollar race. Cecil appears to move slowly, but he secretly calls on turtle cousins who look like him and take turns appearing along the course. Bugs therefore believes he is repeatedly passing the same turtle and is stunned when Cecil is waiting at the finish line.

Cecil returns in Tortoise Wins by a Hare (1943) and Rabbit Transit (1947), giving him three theatrical encounters with Bugs. The first cartoon is a comic variation on Aesop’s tortoise-and-hare fable, but its trick is deception rather than simple perseverance. A common mix-up is confusing Cecil with other speedy Looney Tunes characters such as Road Runner or Speedy Gonzales: Cecil’s defining trait is winning through strategy and impersonation, not raw speed.