Alongside technological advances, the educational potential of artificial intelligence (AI) chatbots and the metaverse has generated significant interest in the field of computer-assisted language learning (CALL). However, despite this heightened interest, there have been no studies that have delved into the effective integration of these two technologies into educational contexts. In response to this concern, this research examined a teacher training course where pre-service teachers designed and used their customized chatbots within the context of the metaverse space. Fifty-five pre-service English teachers were assigned to the chatbot-only group (COG) (n = 31) and the chatbot-metaverse group (CMG) (n = 24). We first explored the CMG's chatbot design works and teaching demonstrations in metaverse spaces and compared them to those of the COG, who developed and utilized chatbots in a physical classroom setting. We further compared their perceptions related to experiences with chatbot-based lesson designing and teaching demonstrations, using a survey and reflection papers. The comparison of design works and teaching demonstrations revealed that while both groups recognized the value and effectiveness of AI chatbots in the language classroom, the participants in the CMG tended to develop more authentic, immersive, and interactive learning tasks, with the metaverse space playing a crucial role as a context. Analysis of a survey and reflection papers indicated that the CMG reported more positive perceptions than the COG. We discussed how the metaverse space might have influenced the way teachers developed and integrated chatbots into their educational contexts. Pedagogical and theoretical implications regarding the combined use of AI chatbot and metaverse technologies were also provided.