On poptropica what do you do with poisedon's trident?

You go to Zeus behind the gates with Hercules and then you go up the mountain then you see Zeus. He will attack you and you have to win.

P.S. After you defeat him you can use the trident and crown. When wearing the crown you grow bigger with spacebar. When using the trident you will light up. If you wear both you look like a glowing giant. If you leave an island or leave a house or something you have to do it again.