A larger than life figure both on and off the court, the announcement from Shaquille O'Neal that he is retiring leaves a void from the basketball aficionado to the casual fan who merely laughed at the antics of the future Hall of Famer.

A four-time NBA champion and Most Valuable Player in 2000, O'Neal made the announcement Wednesday by posting a video on a social website.

A man who enjoyed doing things his own way, it was not surprising he leaked the news in a playful, cryptic manner.

"We did it. Nineteen years baby. I want to thank you very much, that's why I'm telling you first, I'm about to retire. Thank you, talk to you soon," he said in the message.

No formal announcement was immediately made but he told ESPN he would hold a news conference at his home on Friday.

The Superman tattoo on the bicep of the 19-year NBA player provided a vivid insight into the mindset of a man who, refreshingly, does not take himself too seriously.

But as fun-loving as he is off the court, the 7-foot-1 (2.16 metres), 325-pound (147 kilogram) O'Neal was a monster on it.

Following a stellar college career at Louisiana State, O'Neal was made the number one overall pick by the Orlando Magic in the 1992 NBA Draft. He made an immediate impact, being named the league's rookie of the year.

O'Neal spent four years with the Magic before leaving as a free agent for the Los Angeles Lakers, where he won three consecutive titles alongside guard Kobe Bryant.

But he feuded with Bryant, and the Lakers traded him to the Miami Heat in 2004, and in 2006 O'Neal, affectionately known as "Shaq," won his fourth championship.

Since leaving the Heat in 2008, O'Neal played for the Phoenix Suns, Cleveland Cavaliers and most recently, the Boston Celtics.

He commemorated his signing with the Celtics in 2010 by pretending to be a statue in Harvard Square. O'Neal's antics are not eccentric or quirky. They are genuinely funny.

Among O'Neal's many nicknames over the years have been "The Big Aristotle" for his acumen during interviews, "The Diesel," "The Big Daddy," "Superman," The Big Cactus," "The Big Shaqtus" and "The Big Shamrock."

Some were coined by journalists but most were supplied by O'Neal himself.

Despite the shenanigans, O'Neal will be remembered most for his basketball skills. He averaged 23.7 points over his career, a figure stunted over the last few years as age and injuries starting taking a toll on his body.

But in his heyday, few could stop O'Neal once he received the ball in the lane. He was just too big, too muscular, too agile.

As his skills declined over the last few years, many felt it was sad to see one of the game's best players reduced to a supporting role. He averaged 9.2 points this year in an injury-plagued season for the Celtics.

O'Neal has also lived a rich, full life off the court.

He is an accomplished rapper and a part-time policeman, having gone through training with the Los Angeles County Sheriff's Reserve Academy.

O'Neal earned a Masters degree in business administration in 2005, further preparing for the day when he takes the basketball shoes off for the last time.

"It's just something to have on my resume for when I go back into reality," he said of his degree. "Someday I might have to put down a basketball and have a regular 9-to-5 (job) like everybody else."