Short answers, pulled from the story.
The Cleveland Tigers were established in their original form in 1916 as the Cleveland Indians, competing in the Ohio League. They joined the American Professional Football Association (later renamed the National Football League) for the 1920 and 1921 seasons under the Tigers name.
The Cleveland Tigers and Indians roster included two Pro Football Hall of Famers: Jim Thorpe, inducted in 1963, who played as a back and served as player-coach in 1921, and Joe Guyon, inducted in 1966, who played tackle and halfback also in 1921.
The name changed in 1921 for two reasons: Cleveland already had a well-known baseball team using the Indians name since 1915, and three Native American players were signed away from the Canton Bulldogs that year, making the name a natural fit.
The Cleveland Tigers finished 2-4-2 in the 1920 season, placing tenth in the American Professional Football Association. They scored only two touchdowns all season and lost three games by identical 7-0 scores.
Owner Jimmy O'Donnell requested permission to suspend operations for a year in early 1922, which the league granted. When he was unable to post the NFL's required one-thousand-dollar annual guarantee, the league canceled his franchise.
Stan Cofall was a football star at Notre Dame from 1914 to 1916 who later played for the Massillon Tigers. He helped reorganize the Cleveland franchise in 1919, attended the September 1920 founding meeting in Canton, Ohio, and served as the Tigers' player-coach for the first half of the 1920 season. He was also elected vice-president of the American Professional Football Association at its founding.