The Italian media has dubbed Raiola "Mister 300 Million" as he has now negotiated deals worth more than €300m.
"I distrusted him from the moment I met him," former United manager Alex Ferguson said of Raiola after he struck a deal to move Pogba to Juventus in 2012. "There are one or two football agents I simply do not like - and Mino Raiola is one of them."
Raiola fired back: "I put Pogba's interests first... Maybe Ferguson only likes those who obey him."
Raiola's Amsterdam-based firm Maguire took its name from "Jerry Maguire", the 1996 film starring Tom Cruise as a sports agent who gets fired for suggesting his company has taken on too many athletes to properly serve their clients.
The Pogba deal is the third Raiola has struck with United under new manager Jose Mourinho, following the recent signing of striker Zlatan Ibrahimovic and midfielder Henrikh Mkhitaryan as the Portuguese coach seeks to revamp the underperforming squad.
The Italian media has dubbed Raiola "Mister 300 Million" as he has now negotiated deals worth more than €300m- including Pogba's record fee of £89m ($115.42 million).
According to the Goal, Raiola is taking a 20 percent commission for his services, double the usual agent's fee. It said his large commission had held up the talks with United.
Manchester United had already paid out more than £10m agent fees between October and February - the highest amount of all the Premier League clubs even though it did not sign any players during the January transfer window.
Born in Italy, Raiola grew up in the Netherlands, working in his family's Italian restaurant in Haarlem, where the president of the local soccer team ate every week, giving him his first break by appointing the young man sporting director of the club.
Raiola's entry into the lucrative market for top footballers came in 1993 when he - fluent in seven or eight languages - was asked to work as a translator in the transfer of Dutch midfielder Dennis Bergkamp from Ajax Amsterdam to Inter Milan.
Three years later he negotiated his first solo deal, the move of Czech midfielder Pavel Nedved to Lazio.
Raiola did not respond to requests for comment for this article but posted "THE MAN IS UNITED" on his Twitter feed earlier in the day as the Pogba deal was confirmed.
Raiola hit the big time after he dined with Swedish striker Zlatan Ibrahimovic in Amsterdam, negotiating his transfer from Juventus to Inter Milan in 2006 for €25m and then to Barcelona in 2009 for €70m.
Other top players he represents include Belgian striker Romelu Lukaku, French midfielder Blaise Matuidi and Italian striker Mario Balotelli, all up for possible transfers.
Raiola has a reputation for being confrontational, calling former FIFA President Sepp Blatter a "demented dictator" and making a failed bid last year to replace him at the head of world football's governing body.
Napoli president Aurelio De Laurentiis called Raiola a "pain in the backside".
However, Raiola shrugs off the criticism.
"My public image does not interest me because in the world there is always someone who loves you and who hates you for what you say or do," he told Italy's Corriere dello Sport last month.
"I am at the service of my players to whom I give everything, 150 percent of myself ... I want the best for my players."