Wearable electronics incorporating proteins for biocompatibility have garnered significant research attention, given their potential applications in biocompatible medical devices, artificial skin, humanoid robots, and other fields. However, a notable challenge exists, as many wearable electronics currently lack those essential properties due to issues such as non-biological compatibility, as well as insufficient mechanical and conductive performance. Here, we have developed a hybrid keratin (KE) hydrogel by incorporating a liquid metal (LM, eutectic gallium-indium alloy) to design a wearable electronic device with excellent biocompatibility, enhanced conductivity, and good mechanical properties. The resulting keratin liquid metal (KELM) hydrogel demonstrates favorable mechanical characteristics, including good tensile strength (166 kPa), impressive stretchability (2600%), and long-term stability. Furthermore, it exhibits good conductivity (6.84 S∙m⁻¹) and sensitivity as a sensing material (gauge factor (GF) = 7.03), rendering it suitable for constructing high-performance strain sensors. Notably, the KELM hydrogel-based wearable electronics extend their functionality to monitoring marine inhabitants’ health. This innovative application provides new insights for designing the next generation of biomimetic electronic devices, with potential applications in human-machine interfaces, electronic skin, artificial intelligence, and health monitoring.

• The KELM hydrogel exhibits high sensitivity, high elongation and remarkable shape-memory properties.

• The strain sensor exhibits the lowest detection limit (0.5 mm, 1% stretch).

• The strain sensor successfully monitors the traceable heartbeat of scallops.

• The KELM hydrogel expands the preparation strategies of protein hydrogels.