Amazing video of two US sisters aged just four and eight performing a rap battle and taking it very seriously indeed.

In the video, filmed in December 2015, the two face off in a rap battle in the living room of their Washington state home, firing verbal pot shots at one another.

"I'm the original princess/you're a copy of a copy," spits the eight-year-old, with feeling, while stood opposite her younger sibling.

But little sis gives as good as she gets, hitting back with a near incendiary: "You stick your head in soup like it's poop/You stick your head in pee, too."

Despite the fierce exchange, which lasts a couple of minutes, the two siblings kiss and hug in the end.