Elmo is self-described as three-and-a-half years old and characteristically refers to himself in the third person (e.g. "Elmo has a question" rather than, "I have a question"). Sesame Street staff writer Nancy Sans once described Elmo's origins: "There was this extra red puppet lying around and the cast would pick him up sometimes and try to create a personality, but nothing seemed to materialize." The puppet was performed by Caroll Spinney in the early 1970s, Brian Muehl from 1979–1981, and the late Richard Hunt from 1981–1984. Sans continues that "...one day [in 1984], Kevin Clash, a talented puppeteer, raised him up and brought energy and life into Elmo and from that day forward we would all write for Elmo. Kevin's performance inspired the writers to develop Elmo's character. John Tartaglia, Matt Vogel, and Jim Martin have all been secondary performers for the character, providing movement for Elmo's arms and legs, particularly in green-screen shots.