Rocko', the 167-pound Great Dane who stands 7 feet tall on his hind legs, eats 8 cups of food a night and is vying for the title of the world's tallest living dog

                  

Meet Rocko the Great Dane.

Standing seven feet tall on his hind legs and measuring 40 inches from paw to shoulder - Rocko is vying for a place in the Guinness Book of Records as the World's Tallest Living Dog.

For owners Nick Helms and Jessica Williams their giant pet - almost the size of a pony - is proving to be more than a handful.

'We had no idea he was going to be this freakishly large,' Jessica, 26, tells Daily Mail Online exclusively.

'He was bigger than his sisters at eight weeks but we knew that males were usually bigger so we thought it was normal.

'But my best friend has Great Danes and she's had them for a long time and they kept saying how big he was.

'One of their males is larger as well and Rocko surpassed him quickly so we were like, 'holy cr*p he's bigger than him' - it's crazy. We have a giant freak on our hands.'

                 

Boyfriend Nick, 25, adds: 'He was so big we were like - oh my God, is he half Dane or half pony? We couldn't believe it.'

When they got Rocko at eight-weeks-old, he was about the size of a six-month-old Labrador.

And he hasn't stopped growing since.

Now the two-year-old, who is the definition of a gentle giant, can open doors at home and drinks water straight from the kitchen sink.

He munches through about eight cups of dog food a night and loves snacks like jerky.

But for Nick and Jessica, having such a large animal living with them in their small two bed apartment in Reno, Nevada does have its pitfalls.

Jessica, who works as an aesthetician, stands at just five feet three inches and is regularly knocked around by her giant pet.

She's already suffered a black eye when Rocko accidentally head-butted her, and the couple are regularly 'whipped' by the canine's enormous tail.

And the few times Rocko has escaped from his leash he has caused mayhem among passers-by.

Nick, a metal worker and blacksmith, says: 'He's gotten off the leash once or twice.

'We'll take him up to Lake Tahoe with us and we usually leave them off the leash there.

'And he is okay until he finds something that's way cooler than us and he just runs down the beach. There's screaming people. It's a disaster.'

'The worse part is little kids,' Jessica adds. 'People are crossing the road to avoid us, they're grabbing their kids - like he's going to eat them or something.

'It goes from one extreme to the other - it's pretty funny. People want pictures - they'll ask about him.'