Rousey, along with MMA training partners Jessamyn Duke and Marina Shafir, were in a backstage skit with former WWE champs Charlotte Flair, Becky Lynch and Bayley ... where Ronda challenged the rival group to get down.
"You name the time, you name the place," Rousey said. "We're waiting to hear from you."
The story practically writes itself ... Ronda's other BFF, Shayna Baszler, is wrestling in WWE's Mae Young Classic tourney ... and their crew has been calling themselves the Four Horsewomen since they met on "TUF Season 18."
Ric Flair was part of the legendary Four Horsemen of pro wrestling ... and you can bet Charlotte's character ain't gonna be happy with Rousey swagger-jackin' her dad.
We reached out to WWE to see if Ronda's new career is officially on ... so far, no word back.