From Muppet Wiki

Bo Diddley (b. 1928) is an influential rock and roll singer, songwriter, and guitarist. He is often cited as a key figure in the transition of blues into rock and roll, by introducing more insistent, driving rhythms and a hard edged guitar sound.

Diddley appeared in a 1991 Sesame Street sketch spoofing Bo Jackson's "Bo Knows" commercial. He also appeared in that season's celebrity version of "Monster in the Mirror".