Spontaneous or rehersed I remember laughing so much I almost got caught (I was supposed to be in bed long before the Tonight Show came on). Too bad they didn't keep rolling on the CPO Sharky cameras, it would have been nice to see that from the other side.
First time I saw him was as an old friend of Max in Get Smart. He allows the bad guy to get away thinking Max is crazy.
I think that was turned into a two parter because they add-libbed so much.
This makes for interesting reading. Unlike many US stand up comedians, Don Rickles is/was unknown on this side of the pond. We Brits are familiar with many American stand ups, including Chris Rock, Richard Pryor, Jerry Seinfeld, Bill Cosby and Robin Williams amongst others, but Don Rickles is a name I never encountered. I remember this comic coming out in the UK, and buying it, but not having a clue who the guy depicted on the cover was. In those days, with no internet, there was no real way of finding out. Perhaps his humour did not cross the Atlantic very well. Having now read his bio on Wikipedia, I can see no mention of him ever appearing in the UK.
Given your comments I can see he was a well respected comedian in the US and I feel for your loss.
One point - why did Kirby feature him more than once on comic covers? Was this just because he was a fan?
I'm pretty sure Don Rickles' career was mostly stand-up and TV. The other comedians also were in movies. His CPO Sharky show didn't last long so probably never gained fans outside the US.
After Kirby moved to California I always thought he became friends with Rickles, but I've also heard this isn't true. He must have been a fan, at least.
Svengoolie just dedicated his show today, running Rodan, to Don Rickles.
I've noticed at least four characters in the dub are all voiced by Paul Frees.