Charlus Potter's son

The son and only child of Charlus Potter and Dorea Black was a pure-blood wizard.

Nothing else is known about him, though it has been speculated that he is in fact James Potter I, Harry Potter's father. J.K. Rowling has commented that James’ parents were older when they had him; because of this, and because of his family’s wealth and lack of other children, he was quite spoiled. Dorea would have been forty years old in 1960, when James was born, which fits in with Rowling’s comments. However, she also said that James’ parents died of natural causes when they were elderly, but Dorea Potter née Black was only fifty-seven years old when she died.

It is possible that Charlus, Dorea, and their son were simply relatives of James Potter and his father and mother.