To get the Tiny Sporebat, you will need to farm reputation with Sporeggar and become exalted. A guide farming this rep will come out eventually. I do believe however this rep can be gained from killing mobs in the underbog. Primal Life Part 3 is a farming location I use to farm Primal Life, which is also good for leather if you decide to farm rep from the Underbog.
You will be able to purchase the Tiny Sporebat with Glowcap, which can be gather by anyone and isn’t marked on the minimap, though works just like gathering herbs. The Bat sells for 2000 gold on my sever, but others may depend. Within and hour I was able to get 240 glowcap! So roughly 8 pets per hour depending on if anyone else is there or not.
I have a route of where the glowcap spawn, I would highly recommend getting the addons Routes, Gatherer, and the WoWhead database which the database can be downloaded here I believe Wowhead Client.