Epidermal electronics has garnered significant research attention due to its promising applications in wearable human-machine interfaces and intelligent healthcare sensing. However, their widespread use faces challenges due to complex manufacturing processes, high material costs, inadaptability to different skin surfaces, and inadequate reusability. Herein, inspired by the biological reshapability and environmental adaptability of amoeba, an ultra-deformable (≈2600% strain), bioadhesive (adhesive strength ≈3 kPa), strong self-healing (fastest recovery time ≈1s, maximum wound distance ≈5 mm), and electromechanical-durable wearable electronic slime (E-slime) is proposed, which can instantaneously form on-skin electronics in situ to detect body motion and physiological signals. E-slime demonstrates desired sensing performance with high sensitivity (gauge factor 2.95), wide sensing range (up to 400% strain), and low detection limit (≈1% strain), which can seamlessly adhere to the skin and can be easily reused multiple times (≈100 cycles usage). E-slime also enables on-the-fly deployment of motion monitoring tasks at various body locations, showcasing its versatility and reliability for body motion recognition and personal health monitoring. This study holds potential for next-generation green electronics, motion sensing devices, and wearable human-machine interfaces, ultimately helping to ensure healthy lives and promote well-being.