Them mountain oysters
Where'd they come from? Better ask
A'fore ya eat one.
As an 11-year-old immigrant to Kentucky, I was invited by the shriveled and hirsute (but hospitable) crone next door to sample a fresh batch of "mountain oysters" (a.k.a., "prairie oysters"), as a reward after I'd finished mowing her lawn. Leery of anything that might resemble mucoid discharge on the half shell, I asked what a mountain oyster was before accepting. "Why, hog balls," she said, casually.
Oh, blessed suspicion!