Electrons in graphene provide an essentially perfect realization of 2d Dirac fermions. Introducing magnetic impurities then allows to study the so-called pseudogap Kondo effect, where a vanishing host density of states causes a quantum phase transition between phases with screened and unscreened impurity moment.  In the talk, I will discuss the rich Kondo physics in graphene, including orbital degrees of freedom and quantum criticality. In particular, I will analyze the pseudogap Kondo model in the presence of a finite chemical potential.  A striking prediction of the theory is an extreme asymmetry of impurity properties between electron and hole doping over a wide parameter range which can be traced back to the nature of the quantum critical point.