My dad had a number of words and phrases to replace bad ones when swearing at the Philadelphia Eagles playing football. Some were typical: "sugar", "son of a gun", "darn it anyhow"... But he had this one, "Jeepers Pelts", which I think is actually some derivation of a Polish swear. But as a kid I thought there was an animal called Jeeper whose pelt (fur) was poisonous, so if it touched you it would make you mad and say "Jeeper's Pelts!!"
A childhood belief about swearing

others believed things like this
- I used to believe that swearing was just saying, “I swear!”Anon
- Polish war memorial ,I thought it was an instruction.as in to polish— oddsox
- I thought there were some swear words so bad if you said them you would go to jail!— Mexicrat
- I used to believe that people from Holland were called "Hollish", like people from Poland are called "Polish"— Sally
- i could swear eleventeen was a number for the longest time -- it still sounds pretty convincing.— erin
- I thought that a "sugar daddy" was a father who let his kids eat all the sugar they wanted.Anon