Valve cover gasket leaking engine oil, looks to me.
Most likely it is the valve cover gasket that is shot... Best thing to do is clean the area up around it and it will be easier to confirm it is the valve cover gasket leaking.
the OHV stands for Over Head Valve. check your oil level as well to be sure it isn't over full.
post the engine model number, (they are usually stamped on one of the valve covers)