A buncha kids got a SWEET pre-Christmas surprise Wednesday -- 'cause Kobe Bryant brought the gift of Mamba -- and a bunch of books -- to a school in Southern California!!

The Lakers legend dropped by Oxford Prep Academy in Mission Viejo and hung out with a bunch of kids for a great cause.

Kobe's got a new podcast called "The Punies," -- a pod about kids who learn lessons through sports -- which Mamba hopes real-life children can draw from.

Turns out ... one of the teachers at the school is turning those podcasts into an actual curriculum -- so Kobe had to swing by to see it all in person.

We're told Bryant brought the kids books, played games ... and actually watched the kids present projects they'd been workin' on.