Jimmy Fallon and the cast from "Guys with Kids" sing a medley of TV theme songs. It's a cat, it's a cat.. Elephant crashes the pool party. A classic "What on Earth" moment.. Everyone knows how tempting this is. Andre Agassi vs. Ball Girl. Crazy man doing bird calls during victory interview. Celtics Fan Celebration. And the dog's dream came true today.. This is how you know your pizza is authentic. Mariachi surprise.