Was looking at random pictures on a site, and found something that instantly made me think of the upcoming expansion and new battle pets. Look at this picture of a fungal whale that was shown at Blizzcon: http://wow.joystiq.com/2013/11/08/blizz ... -bone-for/ and then google "Nudibranch" and look at the pictures...
Zangarmarsh always was my favorite BC zone and now I just want EVERYTHING fungal whale-themed. Baby fungal whale pet, fungal whale aquatic mount, a jewel-adorned fungal whale statue for my garrison, you name it!
That would be awesome, but sadly we don't have pets in Vash'jir because you can't pet battle underwater. Wish they'd make it happen, I'd gladly swim around looking for tropical fishy pets, whales, sharks, etc.
Technically speaking, if the pets crawled/swam around the sea floor you could pet battle underwater. In Vashj'ir, you can actually run across the sea floor so theoretically you can pet battle as well. The pets would be restricted the sea floor though.