What bully does Percy meet and who is her dad? How and where does Percy battle her?

Percy meets Clarisse, a daughter of Ares, at the volleyball court. Clarisse sneers at him and drags him off to the bathroom, where she tries to push his head towards the toilet bowl. Suddenly something happens, and the toilet shoots water out right at Clarisse. Percy cannot figure out how he did it, but he uses his newfound skill as a threat to make sure Clarisse does not bother him again.