I curious about this one, too. When I was a kid, we had a basset hound named
Sam, and my father took to calling him
Sam Bocephus or just Bocephus. This would've been in the early 1970s.
I don't know where my father got Bocephus. For ages, I thought it must be a name from the bible. My dad was a fan of country music, but I doubt he was aware in the early 1970s of
Hank Williams, Jr.'s nickname. He may have gotten it from the name of
Rod Brasfield's ventriloquist dummy (as mentioned earlier); maybe he heard Brasfield's performances on the Grand Old Opry. I like to think he got it from the folk song thegriffon mentioned, about the boy Bocephus and the bear named
Horatio.