Why did Aristophanes joke that Euripides’ mother was a greengrocer?

The claim that Euripides’ mother was a greengrocer who sold herbs in the marketplace is a tradition that originated from the comedic works of Aristophanes, who frequently used this detail as a recurring joke in his plays.1

It is important to note that this depiction is widely considered a product of Aristophanes’ "masterly unfairness" rather than historical fact. In reality, there is stronger indirect evidence suggesting that Euripides actually came from a well-off family.21

Aristophanes, the primary representative of Old Comedy, was known for his use of merciless invective, bold satire, and outrageous humor to target prominent figures of his time. By mocking Euripides’ background, Aristophanes utilized the genre's characteristic freedom of expression to lampoon the dramatist, whom he frequently parodied in works such as Women at the Thesmophoria and Frogs.231