when did these characters first appear?

[minor muppetz]

Does anybody know when the following characters first appeared:

Little Jerry and The Monotones

Harvey Kneeslapper

Placedo Flamingo

Sonny Friendly

 

[TotallySpiesFan]

Little Jerry and The Monotones

1970

Harvey Kneeslapper

1970

Placedo Flamingo

1986

Sonny Friendly

1986

 

[minor muppetz]

If Little jerry and The Monotones debuted in 1970, did Richard hunt perform Rockin' Richard back then? I thought Richard Hunt pretty much started out as a background performer. I know they are all named after their voice performers, but it's possible that the background monotones weren't named untill later.

 

[MuppetDude]

No; the Monotones' voices have changed depending on who was able to do the recordings; so far, they've been voiced by (just to name a few) Jeff Moss, Chris Cerf, Richard Hunt, and Thad Mumford, and Jerry Nelson.