"Mona Leaves-a" is the episode on the animated show "The Simpsons" in which Mona Penelope Simpson died.
 This episode represents a milestone in the history of the series as Snowball II is killed off, which, excluding the death of Homer's mother in season 19's "Mona Leaves-a", is to date the closest thing to an actual Simpson family member actually being killed off. 
Mona Penelope Simpson (ne Olsen) is a recurring fictional character in the animated television series "The Simpsons". 
