Shaquille O'Neal Trolls Charles Barkley, Can't Get His Belly During Holidays!

Shaquille O'Neal came through with the gifts -- and the jokes -- this holiday season ... giving back in a huge way for more than 500 kids in Atlanta ... and roasting Charles Barkley in the process!!

The Big Aristotle joined Charles and Babcock on "TMZ Live" to talk about his 20th annual Shaq-A-Claus event that went down on Monday ... which included hooking students up with backpacks, Walmart gift cards, toys, clothes, haircuts and more.

On top of that, the extravaganza came with BBQ, DJ music and games.

The Hall of Famer says he first started the yearly holiday bash back in 1992 when his mom asked him to help kids at the local Boys & Girls Club ... so, he went to the nearest Toys "R" Us and bought out the store.

O'Neal loved helping out so much, he decided to do it every year.

"This is all about making the kids happy," Shaq said. "But, more importantly, it's all about making my mother happy ... for her to see her baby boy doing good things like she taught him to do, that right there is one of the best feelings."

"Today is a special day," he added. "I saw a lot of happy kids."

Now, considering Christmas is a time when people tend to put on some holiday weight, we also had to ask how Shaq keeps off the extra pounds -- and naturally, he had to make fun of his "Inside The NBA" co-host.

"I always said to myself, I don't want to have the C.B.O.T.B.B. -- that's the Charles Barkley Over The Belt Belly," Shaq joked. "I never wanna have that, so I just try to eat right and try to stay slim."