His Lou Ferrigno-loving father was responsible for the name but that does not mean it is safe to make the Porto striker angry

There are several versions of how Givanildo Vieira de Souza came to be known as Hulk and some of them prompt amusing images. It has been suggested that Chelsea's prospective signing owes it all to his likeness to Lou Ferrigno, the bodybuilder/actor who played the Incredible Hulk in the American TV series. Or that the nickname was linked to his time in Japan, when his rippling physique carried the green shirt of Tokyo Verdy.

The reality is a little disappointing. The 25-year-old's father, Djovan, was simply a massive fan of the Ferrigno series and he affectionately bestowed the moniker on his son. And it has stuck.

It is pure gold, of course, for the headline writers. When the Porto forward became embroiled in a tunnel brawl against Benfica in December 2009 and was banned for four months by the Portuguese Primeira Liga, he became the "Ineligible Hulk". The phrase "Don't make him angry" was virtually demanded in copy.

Yet behind the muscles and the superhero schtick is a quiet and humble professional, who has put in the hard yards and the air-miles to stand on the brink of his dream move to Chelsea. The basic fee of £38m has been agreed and his personal terms will not represent an obstacle. Why should they when his relatively modest Porto wage is set to rocket to £110,000 a week? The final stages of a transfer can be the most excruciating. Hulk just wants to hold the Chelsea shirt and smile for the cameras.

His journey from Campina Grande in Brazil has taken in rejection by the biggest clubs in his country, a move to Europe at a youthful age, the machinations of agents who have controlled his economic rights and a trawl around unheralded Japanese clubs. But his career found its touchstone when Porto took him from Tokyo Verdy in 2008 – they paid €5.5m to his third-party owners for 50% of his rights – and he has become arguably the most loved player at the Estádio do Dragão since Jardel, another Brazilian who knew his way to goal.

In his four seasons at the club, he has won three league titles and three Portuguese Cups, together with the Europa League in 2011, which represented the final leg of the treble under André Villas-Boas. The goals have poured in. Over the past two seasons, he scored 57 in 91 appearances. But he has also won hearts with the strength of his personality.

After the Europa League triumph, when Villas-Boas was lured away by Chelsea and Atlético Madrid paid €40m to sign the striker Radamel Falcao, the team threatened to break up. But Hulk, the captain, kept his head down and he helped to keep things together. Porto finished as the champions. His captaincy is not of the tub-thumping, grand oration variety. He leads by example.

Hulk had offers to leave last summer but he felt a debt to the Porto president Pinto da Costa, who had dealt sensitively with the great personal tragedy to affect the player. Hulk was shattered when his little niece was left unattended for a fatal moment at a family get-together in August 2010 at the house that he had bought for them in Campina Grande. She fell into the swimming pool and drowned. Hulk was not there but Da Costa told him to return home and take all the time that he needed. Hulk has subsequently celebrated goals with a look up at the heavens.

He is all about family, and is extremely close to his sister and brother, the latter of whom could be expected to accompany him to London. Life was tough for Hulk as he grew up and he recalls how his father, who sold meat at the local market, would wake him in the small hours to take him along, even when he was a mere toddler. Upon their return, Hulk would play futsal for the rest of the day.

Hulk was spotted by an agent playing for a team in Campina Grande and he was taken for a trial at Corinthians only to be passed over. The agent had a connection at Vilanovense in Portugal and he took Hulk there to begin his youth apprenticeship. At the age of 16, Hulk visited the Estádio do Dragão and he declared that, one day, he would play for Porto. Everybody laughed.

Vilanovense could not afford to buy out his rights and, back in Brazil, São Paulo refused to pay a sum that amounted to €18,000 for his signature. He was taken to Vitoria, where he made his debut before, after one further appearance, he was whisked to Japan in 2005. He played for Kawasaki Frontale, Consadole Sapporo and Tokyo Verdy, which had to go down as an unusual grounding for a career at the top level in Europe.

Hulk took the No12 shirt at Porto, in honour of the fans, the team's 12th man, and H12 has become a brand name, a little like Cristiano Ronaldo's CR7. Hulk has a football school in Campina Grande that he called H12 while he has dressed up his sports car with H12 logos.

It would be a mistake, though, to construe him as flash or egotistical and he would also be largely exonerated by the Portuguese Football Federation for his red mist in the tunnel against Benfica, when CCTV footage showed him rucking with stewards. They effectively overruled the League's verdict when they said he had been provoked and should only have been suspended for four matches. The trouble was that when they reached the decision, he had already sat out three months of domestic football.

Hulk felt persecuted after the incident and he has had his problems with referees, feeling that they do not offer him protection. Manchester City fans, though, took a dim view of what they saw as play acting from him during the Europa League meeting in February. "You're not incredible," they sang to him.

Hulk trades on his explosiveness when cutting in from the right, his power and his ability to make the difference in one-on-ones. His arrival at Chelsea would make a difference to Porto's accounts and it would provide yet another link between the clubs.

Chelsea have taken Ricardo Carvalho, Paulo Ferreira and José Bosingwa from Porto for a combined £49.25m, and they paid a total of £18m to secure the release of the managers José Mourinho and Villas-Boas. Of the current squad, Raul Meireles and Henrique Hilário are also ex-Porto.

Porto paid a further €13.5m last summer to buy another chunk of Hulk's economic rights – they now own 85% – and the remaining 15% will need to be squared before the Premier League signs off the transfer. Porto will simply purchase it and then sell. For Hulk, the excitement is tangible.