Yosemite Sam is rumored to be one of the most taxing voices to do. I read once that Mel Blanc‘s son replaced his dad for a while, but that Sam would leave his throat shot, and unable to work for the rest of day. He’s also not as easy to draw as one might suspect. His huge mustache gets in the way of his shoulders, and placing arms can be a challenge; not to mention his tiny feet and short legs. One thing I never really notice was how pigeon toed the character is in the early versions.
