This is a The SpongeBob Chronicles episode.
The two are bored one day when they decide to be superheroes. SpongeBob chooses his name as Super Sponge and Patrick doesn't know what his name is. He has to think for a while...... until he comes up with Star Guy. First, they will battle the thing attacking Squidward. But really, it's his shampoo. Then, they save Larry from getting a sunburn with the power of sunscreen. But it's not your ordinary sunscreen- it's SPONGEscreen, a life-saving sunscreen. The two save Bikini Bottom again.