'Hacksaw' Jim Duggan -- DANCE FLOOR HUMILIATION [VIDEO]

You can't teach old wrestlers new tricks -- and several WWE icons proved it last week, during a hilariously left-footed Zumba class ... and TMZ has obtained the clumsy footage.

"Hacksaw" Jim Duggan ... along with WWE legends like Jimmy "Mouth of the South" Hart, "Rowdy" Roddy Piper, Hillbilly Jim, Pat Patterson, "Mean" Gene Okerlund, Howard Finkel, and Tony Atlas all hit the dance studio in Palm Springs ... and shocker, we're told it's for an upcoming reality show.

Sources tell us the show still doesn't have a home ... but we're told the WWE is hoping to run it on its upcoming network.