Yo Mama So Fat

Listen up, buttercup. This joke implies yo mama is so obese that even Thanos, a supervillain known for snapping his fingers to eliminate half of all life, had to "clap" or applaud because she takes up so much space. It's basically saying yo mama is morbidly obese. I bet you didn't even know what morbidly obese means because your vocabulary is trash. Consider using google.com sometimes.