Cleese says he didn’t find working with Muppets at all disconcerting - despite having the human operators lying at his feet. “Those little creatures are so realistic that it doesn’t seem to require any jump of imagination.”
"Doing the TV show, I had a little scene with Kermit. We did it two or three times and it wasn’t quite right - we were rehearsing our way toward a good take. We did the shot and the director shouted, ‘Cut!’ I knew it was a good one, and without thinking, I patted Kermit on the head!" he relates with a laugh. "One gets sucked into it so easily!"
[From Starlog Magazine July 1985]

Some Muppet and Cleese love. <3