'Real Housewives' Star Kim Zolciak's Mother Waging Legal War -- My Grandkids NEED ME!

In true "Real Housewives of Atlanta" fashion ... Kim Zolciak's getting dragged to court by her own mother -- who's DEMANDING the right to see her four grandchildren, TMZ has learned.

Karen Zolciak filed a Petition For Visitation in GA Superior Court this week -- claiming she used to hang out with her two granddaughters all the time ... baking cookies, making sundaes and spending Christmas in the Bahamas.

Karen's petition also includes her two grandsons -- one of whom was born 2 weeks ago ... and has yet to meet grandma.

Karen claims "Bravo TV needed drama for Kim's show 'Don't Be Tardy For the Wedding'" -- so they "portrayed her as a bad person" to strain the mother-daughter relationship.

Granny Z says it got so bad -- Kim and her new husband -- Kroy Biermann -- had the cops kick her out of their wedding because she used an indoor bathroom, instead of a porta-potty.

Now Karen is fighting back -- telling a GA court that NOT seeing her grandkids will cause "emotional or physical harm" to the kids ... claiming "the girls live such a crazy, abnormal life being on T.V ... they need a normal haven to relax."

A judge has yet to rule on the petition.