This paper extends the result for cooperative output regulation problem for uncertain nonlinear multi-agent systems in output feedback form [2] in the sense that the exosystem generating leader's signal and disturbance is allowed to contain unknown parameter, and parameters in both output feedback systems and exosystem can be arbitrarily large. Since only the information of neighbors and itself is available, it is necessary to construct a distributed control law for the asymptotic tracking of the uncertain leader's signal and the rejection of unknown external disturbances, promising the design of a distributed stabilizer for a multi-input, multi-output nonlinear augmented system with both static and dynamic uncertainties, which is also the main challenge here.