WWE's fondness for Ronda Rousey has been apparent for a long time.
The former UFC Champion appeared at WrestleMania 31, where she jostled with Stephanie McMahon, and attended the Mae Young Classic earlier this year. A clash between her Four Horsewomen of MMA (Rousey, Marina Shafir, Jessamyn Duke, and NXT's Shayna Baszler) and their WWE equivalents has been teased, as has a potential singles match. Whatever the case, she should be considered WWE's top priority when it comes to 2018 signings, at least from a business perspective.
Rousey has never wrestled a match in her life, but she's currently training with Brian Kendrick. As long as she learns enough to not look out of her depth between the ropes, she'll be fine, and her name alone should be enough to draw massive interest.
While losing her last two UFC Fights has dented her reputation, Rousey still has considerable cache, and a bigger star than any WWE employee not named 'John Cena.' She'd be great on a WrestleMania card, where spectacle supersedes workrate on every level, and somebody as skilled as a Becky Lynch or Sasha Banks should be able to carry her to a serviceable bout.