Subject domains are in constant transition as new research and analysis reveal fresh insights, and occasionally, there may be paradigm shifts or new conceptual models. Transdisciplinary approaches may be understood as such a shift, with new approaches for conceptualization, analysis, and problem solving via recombinations of domain fields. Such transitory paradigm-shifting moments remove the usual touchpoints on which a curriculum is structured. There are often few or none of the accepted sequential developmental phases with identified concepts and learning outcomes in book chapters, thematic structures, and historical or chronological ordering. An emergent curriculum requires a different instructional design approach than those that have assumed curricular pre-structures. Based on a year-and-a-half One Health course build, this chapter offers some insights on the processes of defining and developing an emergent curriculum.