I remembered Sam the Robot. He was a strange-looking Muppet that was shown on old Sesame Street books I got when I was a little kid. Sam can be shown on the Sesame Street Dictionary. He was only found on the P and R sections. He was on the word, "robot" where he played jump-rope with Bert and Ernie. He was also on two P words were "perfect" and "plant". In the plant part, Sam tries to water the plants while Prairie Dawn taught us how the plant grows, and in the perfect part, he says, "I am a machine. I am perfect. I do not make mistakles...mistooks...mistics..." I was wondering WHY he was a machine! A robot is a machine, duh!
Whenever Sam's on the old SS books, he appeared on stories where he talked with Maria about her shoes and he shows Big Bird how many five is on the storybook, the "Sesame Street 1-2-3 Storybook". The live shot of him was weird on volume fifteen of the Sesame Street Library.
As if I got the Sesame Street Unpaved book, it only had one photo of Sam in the Whatever Happened To? section. I think I know why Sam is not in the muppeteers section...maybe it's because he wasn't spoken. I discovered some photos of Sam meeting the second Gordon and Susan from the 1972 episode that you guys posted on your old Muppet Central Forum. Now, as I only saw only one small clip featuring Sam at the Museum of Television and Radio, he says, "Hi, Luis!" in Bob's voice as Luis comes out of the Fix-It-Shop on episode #536. My inside reminded me of huge steel-made Muppets on the street, and I think he scare the heck out of me!
I think that Sam is not with all of the Muppets, just only Big Bird and Oscar, and he'd hung around with the human characters during early SS.