Teacher education--as currently practised--is solidly based on a developmental model of growing expertise, where novices move from error to effective practice by replicating the strategies and classroom moves of model teachers. Short timelines and limited opportunities for experience create challenges for students wishing to become teachers. Deleuze's construct of Becoming opens new perspectives on what it means for prospective teachers to explore the notion of Becoming-teacher, where learning about teaching is an encounter with ever-new situations and relationships. This chapter concludes with an invitation to teacher educators to experiment in their own practice, to do with their students, to fully explore the potentialities of Becoming-Teachers.