No one really knows, the closest to a last name he has is his initial "C"
but alot of people say his last name is Chogan.
In the comic series "Johnny the Homicidal Maniac" created by Jhonen Vasquez, the main character Johnny does not have a specified last name. He is simply known as Johnny.
johnnys last name is Cade.
Johnny's true last name is Latour.
Johnny's last name in the outsiders was Cade
Johnny Clay
johnnys last name is Cade.
Johnny's last name is not mentioned in the book.
Bonnie
Cash.
Considering the fact that the boy's real name isn't Squee, we can safely assume the word was simply a noise of fear. Thus it is most likely pronounced "Skwee."
Castle
Snookums the Homicidal Bear :D
Johnny Depp