Teen tries to scare her friends wearing giant Barney head - is left mortified when prank goes very wrong

Mortified Darby Risner is seen floundering about on the floor after her light-hearted prank backfired

A teenage prankster thought it would be hilarious to scare her friends by jumping out wearing a huge Barney head - that was until she got stuck in it.

Mortified Darby Risner is seen floundering about on the floor as her pals struggle through fits of laughter to yank the purple dinosaur costume off her head

The 15-year-old hatched her ridiculous plan at a slumber party on Sunday at her church in Trussville, Alabama.

She popped on the head of Barney the dinosaur - bought with the complete costume by her pastor several years ago - and waited with the prop at the foot of a staircase.

But the character's head slipped over her shoulder and trapped her inside before she could carry out her jokey idea.

Despite numerous attempts from her pals - who even tried to free her using Vaseline - the girls were forced to turn to the fire brigade when the head just wouldn't budge.

Trussville Fire Lieutentant Vince Brunotold told AL.com: "When they walked in, you couldn't help but start laughing.

"We tried to be professional, and she was a little distraught, but we had to giggle about it."

Darby was eventually freed after firefighters cut open the back of the head - allowing her enough wiggle room to get out.

According to local reports, Darby is now fine, telling reporters: "I have laughed about it."

(Source: Mirror)