Apparently this mini pet is less known than I thought! But he’s super easy to obtain – but only during the Darkmoon Faire.
For this task you’ll need 2 Dark Iron Ale mugs from the bar in Blackrock Depths. [I usually buy them out while I'm there for this reason].
After that you go see Morja at the Faire. She’s standing just outside the main area lamenting the loss of her little frog, Jubjub who ran away. Sit one of the Dark Iron Ale Mugs at her feet. Wait a moment and her lost frog will come hopping over [Don't ask me why a frog likes alcohol!]. A moment later she’ll offer the quest [Spawn of Jubjub]. All you need do is trade in the second Dark Iron Ale Mug and she’ll give you an [Unhatched Jubling Egg]. Carry it around for a week and it’ll hatch into a Jubling.
Easy peasy 
Thanks for the reminder! I’ve started working on fleshing out my alts’ pet collections. I already got this one on my main a while back, but I had forgotten how easy it is to get with a little preparation and patience. This one should be no trouble to get on all of the alts.