I've being reading about one theory in particular. That the earliest description of the Sphinx referred to it as 'Horus of the Horizon'. Horus is sometimes depicted with the body of a lion. Khafre is thought to have excavated the Sphinx at some point which implies it already existed during his reign. He possibly resculpted the head due to the excavation effort and the link between Horus and Pharaohs.
All this can sound like pseudoscience so i wondered if any of these theories have any validity.
No, absolutely not. The "arguments" for the water erosion hypothesis are extremely thin, rely on continuously harping on erosion patterns and ignoring that those patterns are perfectly explainable through wind erosion. The arguments for the Khafre (or Khufu's) construction of the Sphinx, including its resonance with Egyptian iconography, mention in Egyptian texts, placement in the burial complex and the rather low population of the Nile during 10,000 BCE, are overwhelming.
As for it being excavated, can you site that? Because I am assuming you are getting a little mixed up--the New Kingdom pharaoh Thutmose IV excavated the Sphinx, one thousand years after it was made. Of course, the Sphinx was literally "excavated" in a way as it was carved out of the bedrock, so perhaps you just saw a poor translation.
