Biological Human-Computer Interaction (Bio-HCI) investigates the dynamic relationship between humans, computers, and biological systems. There has been a growing interest in integrating biological components into wearable human-computer interactions to expand their functional capabilities, material options, and design processes. Researchers have explored novel systems such as biofluid sensing for personal health, sustainable fabrication practices using biomaterials for creating wearables, and integrating living matter into wearable forms. However, as a rapidly growing, multidisciplinary field, Wearable Bio-HCI faces unique challenges and opportunities that demand collective efforts from a diverse group of researchers and practitioners. In this special interest group, we aim to gather researchers who are in this field or interested in integrating Bio-HCI approaches for creating novel interactive wearables. Our goal is to identify, brainstorm, and discuss challenges and opportunities that are unique to wearable Bio-HCI explorations. We aim to generate ideas on community engagement and cross-disciplinary collaboration for future research.