Browser based Moba games

Well the new semester begins and with this i've noticed that I can't run league at my school. The PC's there won't allow you to install odd parts and my Laptop get's blocked from the League servers. I have a 2hour break between my classes and was wondering if there were any browser based Moba games that don't require anything to download. Something like "Adventure time battle party" I just need my Moba fix while i'm at school or i'll lose my mind (I'm on that break as i type this >_