From his early appearances as a nameless monster in the first season to his emergence as a lovable, furry old pal, Grover has been an active and eager assistant in lectures and performances, notably those by Kermit the Frog, Herbert Birdsfoot, and The Amazing Mumford. As Children's Television Workshop researcher Gerald S. Lesser put it in Children and Television: Lessons from Sesame Street, Grover "seeks opportunities to be helpful even when this places great physical and mental burdens upon him; often ends up in total exhaustion as he amiably extends himself to the utmost to co-operate."