What has a heart but no blood?
Answer: An artichoke.
An artichoke has a center commonly called its “heart,” but it obviously has no blood. The riddle works because the word “heart” usually makes us think of a living organ, while here it refers to the tender center of a vegetable.
That double meaning is what makes the clue feel mysterious at first. Once you think beyond people and animals, the answer becomes much easier.
Classic riddles like this often rely on ordinary words being used in a different sense than expected.
