Kroy Biermann says his estranged wife, Kim Zolciak, spends so much time gambling their money away online, she can't take care of their kids ... and now he's asking the judge to order a mental evaluation for her.
According to new legal docs, obtained by TMZ, Kroy says Kim's been showing some "very troubling behavior" that's accelerated in the months leading up to their divorce.
Kroy claims Kim has admitted to him that she's spending a lot of time and money on online gambling and other games of chance, and he claims her "compulsion" has devastated the family financially.