Maybe a God? I think the statue was located at the entrance of the ancient market, but that's an old photograph, so I don't really remember..
The general consensus online seems to be that it is a statue of a giant, used to decorate the facade/entrance of the Odeon of Agrippa:
Ah I see. It couldn't be a Triton (son of Poseidon), since it has feet. A Γίγαντας then, thanks! Maybe Thanos from the Avengers :) I don't remember about that Odeon.. With the Odeon of Herodes Atticus nearby, that seems logical.– gsamarasJun 26, 2019 at 17:22
@gsamaras Wikipedia images says the Triton is the One next to it on the right in the picture.– JoErNanO ♦Jun 26, 2019 at 18:15
Yes, exactly, I would agree.– gsamarasJun 27, 2019 at 6:40