Panda Cub(while i understand how rare this pet it, there are multiple other bear pets that it works for
Dun Murogh Cub,
Hyjal Bear Cub, however some are helped by a battlestone)
Use these bears to level up. Most zones have critters so beasts tend to do well. And the bear's
Hibernate (most bears get it at lvl 4, some at 15) gets you life while you run and grab a snack.
Once you hit 25 with your bear, you can level up other pets easily while watching TV. Start with your 'needs leveled pet, do one move (stun if possible, otherwise some that debuffs the enemy or buffs your team (not just the pet). Then switch to the bear. If the bear has
Roar,
Hibernate, and
Rampage. At the start of a battle, if your health is low, use
Hibernate, then use
Roar (if you are stunned here, use it again), followed by
Rampage. Then rinse and repeat. The only issue occurs if you are stunned on the first turn of the
Rampage, then just use
Roar until
Hibernate is off cooldown.
You can easily use this strategy to level while watching TV as you have 2 moves that go for 3 rounds each. With the 10% safari hat and a 3 hour night of watching TV, i can normally get 2 pets to 25, with minimal effort.
Since there are no high level Mechanical pets, anywhere in Pandaria works, but i personally like Valley of 4 Winds, in the Heartland cause NPC scan goes off when Galleon Spawns, and there are a tons of battlepets around.