"I like it. It’s got a bit of gravitas about it," says Tom Maley, taking a carton of milk out of the fridge and nodding at the model of Alan Shearer's head that sits on top of the appliance. It is Newcastle United's record goalscorer in three-dimensional passport photo form, a serious look on his moulded features. "It was an exercise in trying to get his proportions before I moved his mouth. I did show him that, and he liked it," he says. The more neutral the expression, "the more you look like you."

Maley, 64, is a sculptor and artist best known for designing the statues of Shearer and Sir Bobby Robson that stand outside St. James' Park. The workshop at his self-built home near Morpeth is a monument to an eclectic career. As you pull up to the property you are greeted by Fred and Doug, a fibreglass model of two shirtless, muscular men joined by their bulging abdomens. One's bottom half is black and white and the other's is red and white. "I call them Mack and Tooney now," he says. "We should get a giant version and put it on top of the Tyne Bridge, or on the border between Tyneside and Wearside."

It would certainly be a talking point. Maley is fine company as he rattles through a life imbued with North East history. His mother was from Langley Park, a classmate of Elsie Gray, who later became Lady Elsie Robson. His father, a pit fitter from Sacriston with an interest in Greek and Norse mythology, would regale him with tales from the coal mine, of crawling through 18-inch seams using the most basic tools. "I grew up believing that coalminers were Greek heroes, you know - monstrously strong, as some of them were. It's what bred this area, the strength of the coalminers and the engineering industries that all these lads came from, that we come from."

He left school at 16 to study at Ashington Technical College and became a mechanical engineer, sketching and doodling while working in design departments, drawing offices and on site. He taught himself how to sculpt in his spare time, taking books out of the library to learn how to work in clay, take moulds and cast models in plaster and resin. By his mid-20s it was a passion he juggled with playing drums in a local rock band and building the house he is now drinking his coffee in. "It's amazing what you can do if you don't have a television," he laughs. "I'm not kidding you. That's the secret."

In 1996, his tribute to Jackie Milburn - "another Ashington lad, I'm an Ashington lad" - went on display at Woodhorn Museum. Sir John Hall saw it and brought it to St. James', where it stood on the plinth Robson now perches on. It came down in 1999 and has never been reinstalled. "Hint, hint," he grins. It earned him a commission to commemorate Wilf Mannion at Middlesbrough's Riverside Stadium, and he drives past Robin of Pegswood - a bronze portrayal of a miner, posing like an archer on a curved steel girder - every day.

"Once you've produced these pieces, they're kind of not yours anymore. They belong to the public. I don't refer to them as mine," he says. Seeing people take photos of or with his work brings some fulfilment in a subjective vocation that is "not for the faint hearted or the thin skinned. I'd love to have been in the crowd when Michelangelo unveiled David, arguably the greatest sculptor and sculpture of all time. There'll have been somebody in the crowd going, 'load of *****!'" he chuckles. "You can't win."

We take a seat upstairs next to a table stacked with models of different scales, his "little testbeds", among them a minimalist version of Locomotion No. 1 that was installed at the Visqueen site in Stockton and a welded hawk made by his father, who was self-taught too. There are pencil drawings on the walls, some of which depict hippocampi in various poses. Two illustrations feature the numbers five and four; Maley is the fourth of five children who grew up at number 54.

Another, of some kind of fungi in human form clutching a spear, catches the eye. "This one on the end is a bit of fun. This is the concept of the very first caveman to accidentally discover magic mushrooms. He's tripping on the magic mushrooms and this is what he looks like in his own head. He's got a girlfriend called Delia and he's called Zach, so it's Zach and Delia: psychedelia. I've never tried magic mushrooms. I might before I die, you know?"

How do you come up with these ideas? "Well, some would say by eating magic mushrooms!" he jokes. "But with me, it's not. It just started with daft stories my dad would tell me as a kid. He fired my imagination. And then just reading Greek mythology, Norse mythology." As a child, he would study Frank Frazetta's Conan the Barbarian covers and the artwork on Marvel comics. "It keeps me out the pub," he shrugs. "Not for long."

On a sheet-covered table to Maley’s right are two striking pieces from his "techno-mythology-type series." One maquette, 1carus, shows an athletic figure wearing a crash helmet whose arms flail behind him in the shape of exhausts. It was unveiled in the paddock at Silverstone in 2014. The other, Horse Power, is a "kind of steampunk, techno" reimagination of a seahorse whose tail is turbine-esque - a tribute to Sir Charles Parsons, inventor of the steam turbine in Newcastle. He enthuses about the work of William Armstrong, George Stephenson and Charles Sheridan Swan. "Every time you switch your light on or stick a plug in the wall, you owe a debt to Charles Parsons of Newcastle. I just think we don't celebrate that enough," he says. "We're awash with brilliant engineers and we take them all for granted. I don't. My background is mechanical engineering - that's how I started out - so these guys are my heroes."

Horse Power reflects Maley's long-held interest in hippocampi. "I'm a bit mad about them," he says. The mythical creature is woven into the area's history and is a component of United's new crest, which was unveiled earlier this month. "In the late 1300s, Newcastle adopted the seahorse - not one, but two - on their civic heraldic coat of arms, which was issued by royal approval. It was the first seahorse ever to be used on a coat of arms in the UK. It was hundreds of years before anybody else used them."

He believes Newcastle is the only city or town to have two on their coat of arms. "It represents, for me, the spirit of Tyneside - the seafaring city, boat builders, filling boats full of coal, exporting that all around the world. What developed from there, the industry that came from the coal and the ship building, is what modern-day Tyneside is built on. There's no giant football stadium without all of that. It's all built on that."

Maley says he has "books full" of hippocampi drawings, "ridiculous amounts of sketches of them." Singapore, he explains, is noted for its merlion mascot, which has the head of a lion and the body of a fish. He reckons hippocampi can be similarly symbolic in Newcastle. "It really is our identity. The magpie's just something that came along in the last 100 years, right? We are the seahorse. I really do believe it captures the spirit and industry of Tyneside better than anything."

It leads us to a small diorama to his left, a work in progress he calls Seahorse Rising featuring 12 hippocampi - "11 players, plus one manager," he says. "In Greek mythology, Poseidon's chariot is pulled by seahorses. But now, these seahorses are liberated, they're free, they're happy and playing football in the park. The concept is the whole group can be whichever team you consider to be a period when the seahorse was rising - and by that, I mean the club doing well."

For him it's the Fairs Cup-winning team of 1969. To others, it might be Kevin Keegan's Entertainers or Eddie Howe's Carabao Cup winners. He points at one of the 12. "He can be whoever or whatever you want it to be. He can be the player you've always loved, he can be you kicking around in the park. He's your favourite team, your favourite manager. He's just the spirit of Tyneside, and the spirit of the football club as well."

He would love the chance to upscale the diorama to sit alongside his other Newcastle-related sculptures. A bronze bust of Robson, created as a surprise and modelled from photographs Maley took, sits just inside the players' entrance in the Milburn Stand. Robson's south-facing statue outside the stadium was developed from sketches and built using 3D laser scanning in 2012. "As you come round the corner, you're looking up at him. Where we've sighted him, he's looking across the city, and that was deliberate. It's stood the test of time."

There are intricacies in the details. Robson was often pictured on the touchline with his hands in his pockets, which is reflected in bronze. Shearer's statue, which was moved from Barrack Road to stand alongside his former manager in 2022, shows him holding up a single finger rather than his whole palm. It was a finer point Maley had to convince Shearer about. "In a photograph, it doesn't matter as much. But in terms of a static piece of sculpture that you're trying to bring to life, that…" he says, lifting a finger, "has got more tension than that," he adds, raising his palm. "It's more aggressive, more dynamic. It's a tensed fist. You can't point that finger without making a fist."

The Robson and Shearer statues stand at nine feet six inches. Technology has streamlined the sculpting process, removing seam lines from moulds and adding precision, though Maley still likes to work at workshop size - about three feet tall - before scaling up. "The human brain's used to seeing life-sized people. We're not used to seeing giants. If you're modelling a giant, you're modelling something you've never seen before. It's very difficult and you'll get it wrong unless you measure, measure, measure."

On the way back outside for a final glance at Mack and Tooney we pass a clay model of Wayne Rooney on the countertop, arms outstretched after scoring his overhead kick in the Manchester derby in 2011. Rooney himself possesses the finished piece. Back-to-back stainless steel dollar signs join to make a sculpture inspired by Robert Indiana's pop art piece LOVE. There is a Shearer bust too, identical to the one used on his statue. "I don't think that looks as much like him as the one on top of the fridge, but it's near enough."

If money was no object, he'd produce a concept he has come up with based around the Formula One track at the Hard Rock Stadium in Miami Gardens, Florida and "just drop it, like a Banksy. And in the fullness of time, if I live long enough, I hope I'll still see Jackie back up there at St. James' Park," he says, with a nod to a 1994 replica of the great man's head which sits, cracked, in the corner. "I'll never give up on Jackie, because he's the bookend of my career. He's what started it all. I've got a very strong affinity. I haven't given up on getting him back there.

"I've had a few successes, right, but I'm still hungry for it. I'm 64 and I'm still as enthusiastic now as I was when I started out doing this stuff in the '90s. I'm still going for it."

There is scope, Maley feels, for a Newcastle sculpture to rival Gateshead's Angel of the North by Antony Gormley. He would love for it to be a large-scale Horse Power. Hippocampi are a great vehicle for artists, he says, rooted in superstition and mythology. "But that's what all the best stories are. So we keep these stories going." He lists depictions of them around the city: on the Prudhoe Chare sculpture wall off Northumberland Street, on the mural just across from there on Northumberland Road, on a wooden carving on the top floor of the library.

"They're there, they're around. We just need more of them, that's all. There should be one on every street corner," he laughs. "And I know a guy…"