I watched the newly-restored Disney short Mickey’s Kangaroo and was shocked to hear Pluto talking. Well, technically, he looks directly at the viewer in a somewhat unnerving way and seemingly transmits his thoughts to us telepathically, but still. It’s a surprisingly gruff voice. I can see why they immediately abandoned this and had him keep his thoughts to himself for the next 90 years.
I remembered hearing Snoopy talk in a Peanuts cartoon once where they go in the opposite direction and give him a slightly nebbish young guy voice so I went to look that up, found this video, and was equally shocked to see a fleeting glimpse of Lucy and Linus Van Pelt’s parents. Behold: