Minnie Szyslak is the sister of Moe Szyslak and is a mattress saleswoman and food critic.
As a child, Minnie would appear in commercials for her father's business, Mattress King, alongside her family.
She and her brother behaved spitefully towards their elder brother, Moe when he went to make peace with his father, Morty. Marge convinced the family to have dinner at the Simpsons' house. During this, they began to quarrel before Homer convinced them that they were a family, after showing an old commercial.
Morty announced his retirement from the mattress industry, and each of his three children inherited a store. After Minnie and Marv abridged one of Moe's mattress commercials to damage his reputation, a sibling rivalry emerged: Marv and Minnie seeking to undermine Moe's shop and vice-versa.
The feud culminated in a standoff between Moe and his family at the Mattress King Warehouse, in which a manic Moe threatened to through a jar of bedbugs over the mattresses. After Marge talked him out of doing so, a calmer Moe would accidentally drop the jar of bugs, causing Minnie and the others to flee the warehouse.