A funny video has emerged of a famous 'mad scientist' YouTuber who built a remote controlled, fire breathing, smoke blowing dragon and inadvertently knocks his six-year-old son over with it.

Jacob The Mad Scientist from Australia was filming an episode of Make Science Fun for his YouTube channel when the minor incident happened.

One of Jacob's passions is to make Science come alive, and he loves finding toys and souping or 'turbo'ing' them up.

The remote controlled dragon was made from an Ikea soft toy dragon, a large remote controlled truck, smoke machine and gas bottle. The dragon flaps its wings and blows fire and smoke from its mouth.