Yo mama so fat,
She doesn't fit in a Titan's mouth.
(Attack on Titan; Shingeki no Kyojin)
Yo Mama and the Titan
Explanation
Explain Bear
Listen up, you chucklehead. This joke is all about how incredibly obese your mother is. She is so large that she cannot even fit into the mouth of a Titan from "Attack on Titan", and those things are huge! It's an insult, get it? You probably smell bad yourself.
I made this joke
It's a reference people* Correction