The emergence of artificial intelligence (AI) as a transformative force in education has fundamentally altered the landscape of teaching and learning, compelling educational systems worldwide to reconsider what it means to prepare effective teachers for the 21st century. In Nigeria, where teacher education faces longstanding structural, methodological, and resource challenges, the advent of the human-AI hybrid classroom represents both a formidable challenge and a historic opportunity. This paper argues that addressing this challenge requires not incremental adjustment but a genuinely transformative reconceptualisation of teacher education,  in curriculum design, pedagogical orientation, institutional culture, and policy direction. Drawing on the Technological Pedagogical Content Knowledge (TPACK) framework, Mezirow’s Transformative Learning Theory, and Vygotsky’s Sociocultural Theory, and integrating evidence from global and Nigerian educational contexts, the paper examines the conceptual, structural, and practical dimensions of preparing Nigerian teachers for human-AI hybrid learning environments. It further proposes the REACH Framework, a five-dimensional model for reimagining Nigerian teacher preparation, and derives implications for institutional practice, professional governance, and national education policy. The paper concluded that the future of Nigerian education depends not on whether AI enters the classroom, but on whether teachers are adequately prepared to navigate, humanise, and lead learning in AI-augmented environments. 

Keywords: Artificial Intelligence in Education, Human-AI Hybrid Classroom, Teacher Education, Transformative Pedagogy.