Spiderpig

This mural shows a free body diagram of Spider-pig. The weight force mg pulls him down, but Homer Simpson's applied force keeps him moving forward on the ceiling. Since Homer can't perfectly balance the weight force, the pig also exerts some force on the ceiling, which exerts a normal force back (which balances the forces on the pig in the vertical direction so it does not move up/down and the ceiling is not crushed). If Spider-pig tried to swing from a web, his weight would create a force greater than the maximum tension the string could withstand, causing it to snap/

The actual corresponding words from The Simpsons are: Spiderpig, Spiderpig, Does whatever Spiderpig does. Can he swing from a web? No he can't. He's a pig. Look out! It's Spiderpig.