George Burns makes a brief uncredited cameo appearance, as the voice of Mister Ed doing an impression of George Burns.
During the kid's party they play the old folk song, now kids song "The Old Gray Mare"
It's not known who actually wrote the "The Old Gray Mare". It's been attributed to Steven Foster or Frank Panella. But it can really be confirmed who wrote the tune. But there actually was an "Old Gray Mare".
A gray horse named Lady Suffolk in the 1840's is thought to be the inspiration for the song. But that inspiration had to come from her time after her racing career. She could run with a sulky or under a saddle. She won 89 of her 162 races. And she finished second 56 times. She also set what was then the world record. She was the first trotter to finish the mile in under two minutes thirty seconds with a rider. She raced sixteen seasons until she died in 1855 at 22 years of age.