He's so big he sleeps on an adult-sized mattress, and weighs in at just over 76 kg.
He eats a special diet of chicken and rice, sleeps for 22 hours a day and stands at more than 7 feet tall.
Now, Major the gentle giant is in the running to take the title of the world's tallest dog.
The three-year-old Great Dane is the baby of Brian and Julie Williams from South Wales, and the couple say the sweet-natured dog gets comments from strangers wherever he goes.
"He is the biggest-hearted dog in the world. He is such a fantastic animal. People love seeing him," Mr Williams told the Daily Mail.
"We bought him as a pup and he has been with us ever since. He has got free reign of the place if he wants to go out, he isn't locked indoors," he said.
"He's afraid of his own shadow, he's absolutely great with kids and an absolute star.
"He brings us a lot of happiness and is so easy to look after. He's just got a terrific temperament and never gives us a minute's problems."
Officials from Guiness are due to visit the family soon to determine whether Major will win the talllest dog title.
While his size is impressive, winning the world record still isn't a walk in the park - he's up against two other Great Danes, Freddy, from Southend in Essex, and Rocco, from Nevada in the US, for the coveted title.
The previous tallest dog record holder, George, was from Arizona and weighed in at a whopping 107 kg.
However, regardless of whether he wins the title Major is still a winner to his doting owners.
"It's going to be fun to find out if he's the tallest," Mr Williams told the Daily Mail. "But he's top dog to us anyway."