Note: I have taken creative liberty to distort some facts (which are, interestingly, about the myths.)
He was dressed in a white dhoti carefully tucked near his navel. The sacred thread ran down his left shoulder with the Brahma knot exactly above his dark brown nipple. His chest was moving as he placed the deer on the ground in the ashram.
"Here is the prey I got today, father." he said to his sage father who was deep in meditation.
Sage Drona slowly opened his eyes and looked at his son. He felt proud today for what he had achieved for his son. The gold anklets Ashwathama was wearing were from Drupada's treasure - the same Drupada who had denied helping him years ago. The same Drupada who Drona had ransacked using his disciples and snatched half the kingdom from.
Drona's eyes felt heavy with tears. What had he done wrong, he thought. He just saw his wife mixing flour with water and feeding her son this new form of milk. He just wanted it to be better.
"What happened, father?", Ashwatthama shook his father's arm. The silver hair on Drona's arm perfectly matched the colour of the ash smeared on the loose skin.
As the toddler walked out of the yadnya fire, it strutted its way to the king. Without his upper garment, ornaments and his crown, the king looked like a glorified beggar. An asker he was. With a strong wish that he begged to be fulfilled. He picked up the baby and looked into his eyes - "You will avenge my insult", Drupada said into the baby's left ear softly. Either the baby understood it perfectly or not at all. But it let out a giggle and reached for his father's half-grey beard. The sages gathered around the baby to sprinkle holy water on his face.
Several years later, the baby grew up to be an able-bodied warrior, Drishtadyumna. As Sage Drona sat on the battlefield howling over his son's death, the now-warrior baby held the sage by his hair and chopped his head off with the stroke of a sword. This time, blood splattered over the baby's face.
As the baby played in the father's arms, a little girl walked out of the fire. Nobody seemed to notice her. Dressed in a white silk sari, she seemed to be comfortable. Her hands lept into the air for the king's attention. The king was too engrossed getting his beard fondled. The girl pulled up the end of her sari over her head and squatted on the floor.
Little did she know that she would grow up to be Draupadi who would in fact be the crucial turning point that would eventually lead to Sage Drona's death.
Drupada and Drona were both fathers. Ashwatthama, Draupadi and Dhristadyumna were all children to their fathers. The war of Kurukshetra saw the three of them continuing where their fathers had left off.