While several studies explore whether librarians think of themselves as teachers, how librarians construct their teacher identities has received less attention in the literature. This project used semi-structured interviews with eighteen academic librarians in the United States to gain a sense of their teaching personas and how these have developed and evolved over time. The participants valued authenticity but were also able to quickly adapt their personas to different contexts. Librarians wish to be seen as friendly experts and develop their values-based teaching personas slowly over the course of their careers. The results of this study can help shape professional development efforts aimed at librarians who teach as well as provide guidance to library and information science students as they learn about information literacy instruction.