Warning!! Don’t touch the head of a venomous snake.
In 2014, Chef Peng Fan was preparing a special dish for his hungry customers when the unthinkable happened. He was cooking a dish of roast cobra and had cut the head off a live venomous snake in preparation for the dish.
About 20 minutes later, he picked up the head to throw it in the bin when it bit him and injected its venom into his arm. People in the dining room heard him scream from the kitchen and ran to help him.
The effects of the venom were quick, and he died from asphyxiation before he could get anti-venom. And to answer the question, a snakes head can stay functional for up to an hour or more after decapitation.