Slowest-Drawing Ed is a cowpoke who appears in the "Elmo the Musical" segment, "Cowboy the Musical".
Elmo imagines himself as a cowboy in the west, where he's greeted by Ed and Fastest-Drawing Fred. They point out that in these parts, a cowboy needs a special skill to be named after. Ed receives his by being a slow drawer. He also is shown being able to ride a bonking steed and finding reasonably priced cowboy chaps.