The first Moonshadow was a San Francisco poet who met and fell in love with Sunflower in 1966 or '67. Sunflower was a drugged-out, burnt-out hippie who had trouble relating to anything, but Moonshadow managed to bring her attention back to humanity and life. They became extremely close.
Moonshadow was soon drafted to Vietnam, and he chose to go, hoping that he could change things and bring about peace by being part of the action. Unfortunately, he was killed by a bullet through the forehead not long after.
This broke the already-hurt Sunflower, whose best friend had already been killed in the military. Still, she named her son after the original Moonshadow as a sign of hope.
He appeared to Moonshadow the younger on a couple occasions as a spirit or vision (Moon was also often visited by visions of his mother and Aunt Ettie) when he was in dire straits, such as when he was about to be lowered into boiling vats in a concentration camp, or when he was held prisoner by Pobidiah Unkshuss. On the first occasion, Moon blamed him for his Romanticism, which only got Moon into trouble, and had gotten the elder Moon killed. But the elder Moonshadow made it clear that his optimism had helped, because they had led to Sunflower's own hopes, as embodied in her son, which was in a way his spiritual gift to her.