I just came across an episode of HOUNDCATS, a '70s cartoon that I wasn't familiar with (odd because I grew up around that timeframe). I'd heard that Joe was a regular voice on some cartoons but this was the first time I'd seen one. Actually, this was much too hokey for me to watch most of it, but I did watch enough so as to tell which character Joe voiced.
Then I looked for, and found, an example of Joe voicing Babu in the I DREAM OF JEANNIE cartoon. (Babu actually kind of looks like Joe!)
All of this reinforces that Joe was one of those actors who always plays the same character no matter what part they're in!