The mythical creature with a human head and lion’s body known for posing riddles is the sphinx.
The best-known Greek sphinx was a female monster with a woman’s head, a lion’s body, and wings. According to the Oedipus myth, she guarded the road to Thebes and challenged travelers with a riddle. Those who failed were killed, while Oedipus solved the famous question by answering “man,” describing humanity’s four-legged, two-legged, and three-legged stages of life.
Sphinx traditions are older and broader than the Greek Oedipus story. In ancient Egyptian art, sphinxes were usually represented as powerful guardian figures with a human or royal head and a lion’s body. The Great Sphinx of Giza, probably created during Egypt’s Old Kingdom around 2500 BC, is the most famous surviving example.
A common mistake is to assume every sphinx has wings or is female. Those details fit the Greek monster, while Egyptian sphinxes were generally wingless and often male. The defining combination in this question—human head, lion body, and riddles—points to the sphinx rather than a griffin, chimera, or Minotaur.