A martial arts fan has created a terrifying weapon - an electrified sword with a built-in stun gun.
The electrified double-edged knife delivers a 110 volt shock whenever the blade touches skin.
It was built by American student Jonathan Johnson, 21, who posted videos of the weapon in action on YouTube.
The blade - which charges by plugging into the wall - would be illegal in Britain.
Mr Johnson, from Baton Rouge, Louisiana, said: ‘I've always liked to build things and make crazy awesome weapons.
‘I thought it would be cool to build and show off to my friends. I never expected it to blow up as big as it has.’
The sword has plastic bolts separating the blades so the current can transfer across the blades - causing the distinctive crackle and blue sparks of an electrical stun gun.
Mr Johnson says that it only took him about five hours to make, at a cost of around £30.
The zany inventor tested out his potentially deadly device - by getting his friend to hit him with it.
In another clip posted on YouTube, Jonathan gets a pal to touch the sparking sword to his stomach, causing him to double up in pain.
Seconds later, he hits the electric blade with two normal metal swords, before dropping the swords and collapsing to the floor in agony, as the current surged through his body.
Mr Johnson - whose videos have racked up two million hits on YouTube - said: ‘The pain wasn't too bad in the stomach.
‘It kind of felt more burning than stinging from the electricity.
‘When I hit it with the two swords, it felt like spikes going through my hands wrist and into my forearms - that's the reason I couldn't hold on to the swords.
‘I wouldn't do that again - not for a million dollars.’
Stun guns are considered ‘less-lethal’ weapons, and are commonly used by police to subdue a threat.
The stun-gun sword uses a low-powered stun gun built into the handle, which is made from electrical tape and insulating rubber.
It delivers a direct current (DC) to whatever conductive material touches both blades - including human flesh.
The two blades are separated by nylon bolts, and have not been sharpened, making the incredibly dangerous weapon slightly less deadly.