So I just did the hydra while human on my naked zwei; no golem. Quit and reload and he was there. So yeah. He's just not there after killing the hydra until you refresh the world. Also: Killing the hydra took as many attacks as he had heads. Seriously, one shot, one head. It was fucking awesome. Also this game approves of my strength build apparently; tonight I got both a black knight greatsword, a black knight shield (before doing quelaag even, hah), and a stone greatsword.