Yo mama so fat, I took a picture of her last year, and it is still printing.
Yo Mama's Everlasting Photo
Explanation
Explain Bear
Listen up, buttercup. This joke is sayin' yo mama is so dang big that when someone took a picture of her, the printer's been workin' non-stop for a WHOLE YEAR. That's like, a really long time, even for you to understand. Get it now, genius?