In John's gospel, Jesus is the Lamb of God (1:29), Jesus is the gate by which the sheep enter (10:7), and he is, of course, the good shepherd (10:11). So he plays every role of that metaphor. Of course clearly in chapter 10 and in his commands to Peter in chapter 21 people are his sheep. But it seems people are sheep only insofar as they participate in the life of the Lamb. Thus, Jesus controls the boundaries of his flock (gate) and he leads his flock (good shepherd), but also the shape of his life defines 'sheep-hood' itself. Peter's charge to feed Jesus' lambs, take care of his sheep and feed his sheep are founded in his love of Jesus (x3) and in the fact that, like Jesus, one day he will stretch out his hands, be dressed and taken where he does not want to go, glorifying God in his death (21:15-19).
Jesus is the sheep par excellence.