Five minutes after the cobra's head was severed from its body, the seemingly lifeless reptile staged a sudden retaliatory strike, sinking its fangs deep into the hand of the man who had killed it. The vicious bite put the elderly man's life in imminent peril. "The head was already cut off, how could it still bite?" he murmured.

This incident occurred on a sweltering afternoon in May, when a 72-year-old angler surnamed Zhang deliberately chose a secluded riverside spot for fishing, unaware he had wandered into a cobra's territory.

Drawing on decades of outdoor experience, Zhang reasoned that retreating might provoke an attack and be more perilous. Therefore, he gingerly pulled out a digging shovel he carried with him, struck the cobra as it reared to attack, and flung the reptile aside. Fearing a counterstrike, Zhang pressed his attack, severing the snake's head, chinanews.com reported.

Surprisingly, when Zhang reached down to pick up the severed snake head, the detached cranial segment, which had been separated from the body for about five minutes, suddenly gaped its jaws wide, sinking its venomous fangs deep into his palm, according to the report.

Recalling the moment later, Zhang said it felt "like an electric shock," the pain wrenching a cry from him. The snake, far from releasing its grip after the bite, even clung tenaciously to his hand, Zhang added.

He shook off the head with a violent flick and rushed to the hospital. The wound quickly darkened and swelled, and within less than 20 minutes, he began experiencing chest tightness, blurred vision, nausea, and vomiting, chinanews.com reported.

After receiving emergency preliminary treatment at a local hospital, Zhang was rapidly transferred to the emergency medicine department of Qiantang campus, Zhejiang Provincial Hospital of Traditional Chinese Medicine.

Upon admission, severe swelling ballooned his entire left arm, stretching from his thumb all the way to his shoulder. The skin around the bite had turned black and necrotic, with a markedly elevated local temperature, the report said.

Meanwhile, Zhang exhibited systemic symptoms triggered by cobra venom's triple toxic effects, putting his life at grave risk without urgent intervention.

Consequently, doctors performed debridement surgery before the venom could cause irreversible tissue necrosis. Following the operation, and after two months of treatment wound repair, Zhang's left hand was saved, chinanews.com reported.

In the postoperative period, Zhang dared not move his hand, suffered by pain and dread, and suffered three consecutive nights of nightmares in which a headless snake pursued him relentlessly. He confessed, "I will never act recklessly again. The price I paid is far too steep."

As of now, Zhang has made a full recovery and been discharged from the hospital.

Citing Wang Yonggao, an expert in wound and vascular surgery at Zhejiang Provincial Hospital of Traditional Chinese Medicine, the report explained that even after a reptile's head is severed from its body, spinal reflexes can keep it displaying aggressive behavior for tens of minutes or even longer. The snake head can still bite with force, and its venom glands remain capable of injecting venom, the report said.