Who is aunt in Harry Potter and the Prisoner of Azkaban?

In "Harry Potter and the Prisoner of Azkaban," Harry doesn't have an aunt in the traditional sense. The closest relative he lives with is his aunt Petunia Dursley, who is his mother's sister.

It's important to note that Harry's aunt Petunia is not a kind or supportive figure. She's shown to be quite cruel and neglectful towards Harry, constantly reminding him of his "freakishness" and the fact that he's a wizard.