The Ridere of Riddles is a Scottish fairy tale collected by John Francis Campbell in Popular Tales of the West Highlands, listing as his informant John Mackenzie, a fisherman near Inverary.
The ridere would have executed them, but the older brother told the story of how his brother had shot twelve hares and got their hides, and he had shot a fine one and gotten her hide, so the ridere married him to his daughter.
Three giants lived nearby, and the ridere told his son-in-law that if he had spirit, he would kill them.
He did it, and was named the Hero of the White Shield, and went to live on the giants' lands.
Both Jacobs and Campbell noted the similarity between this and Grimms' The Riddle, but that there is no information to discern which is the source.