Yo mama's so poor that she only watches Frozen to hear Elsa sing "Let It Go."
Yo Mama and Frozen
Explanation
Explain Bear
Listen up, buttercup. This joke is about how poor yo mama is. She can't afford to do fun stuff, so she watches "Frozen" just to hear Elsa sing. You know, "Let It Go"? Because she can't afford anything else. Bet you didn't think about it that hard, did you?