Long-Tailed Mole
Source: Pet Battle. Thought by many to be nothing more than the subject of children's nursery rhymes, the long-tailed mole is very much real. Critter type. Can be found outside of booty bay as a secondary quite easily.
The Long-tailed Mole is a wild battle pet found primarily in caves and underground areas across multiple continents, and can also be spotted in the Un'Goro Crater region.
Guide awaiting review
Head to Un'Goro Crater
Travel to Un'Goro Crater, where a small number of Long-tailed Moles wander near the oil fields. If no moles are spawning in the open area, locate the nearby cave close to the oil fields and clear out all the critters inside — the cave contains only cockroaches and Long-tailed Moles.
Trigger a Fresh Spawn
After clearing the critters inside the cave, head back outside and defeat a few more critters near the oil fields. This forces new battle pet spawns, and a Long-tailed Mole — potentially of uncommon quality — should appear among the next spawns.
Try Booty Bay as Backup
If Un'Goro proves unproductive, Long-tailed Moles can also appear as secondary pets in battles fought outside of Booty Bay, making that area a reliable alternative location to find one.
Tips
The Long-tailed Mole is the only critter found in Ironforge, making it required for the Big City Pet Brawlin' - Alliance achievement.