Important: Because of the low amount of pet XP, I really only use the Legendary pet battles to level my 24 pets to 25, instead of wasting the nice XP you get from the trainers to do the same thing. This also works nicely in case RNG makes your two pets totally bomb.
There are 10 pets that you fight throughout this journey, and those pets are either Aquatic, Beast, or Critter. To simplify this guide, I'll split them by their type.
The most important pet for you to get to max level is any pet that has Life Exchange. I personally use the Sprite Darter Hatchling, but you can also use the Mini-Mindslayer, the Nether Faerie Dragon, or the Ethereal Soul-Trader. Why? Well, because these pets have a huge pool, and you will knock them down to about half their health just by using Life Exchange; also giving your pet the time to get to full health.
Level 24 pet to level (make it go out first) - should not be a Critter.
Sprite Darter (or other pet; just make sure it has Life Exchange).
Anubisath Idol (With Demolish, Sandstorm, and Rupture).
Start with the pet you want XP for. Do one move, then switch to the Sprite Darter. Let it get hit a couple times, use Life Exchange, keep knocking the legendary's HP down till your Darter dies. Switch to the Idol; put up Sandstorm to limit DoT damages and their accuracy, use Rupture on cooldown, and use Demolish in between.
Greyhoof - Found in the southern part of Valley of the Four Winds, a mini Mushan.
Abilities: Hoof, Roar, Trample.
Gorespine - The hardest of the three beasts in my opinion; his attack power is quite high so he hits really hard. You may lose both your Idol and your Darter, but you can finish him off with your 24, I've done it. Found in southwest Dread Wastes. He's a silent hedgehog.
Abilities: Rip, Scratch, Spiked Skin
Kafi - Found north of Winter's Blossom in Kun-Lai Summit, a Summit Kid.
Abilities: Gnaw, Headbutt, Leap
Level 24 pet to level (make it go out first) - should not be Undead.
Sprite Darter (or other Life Exchange pet)
Chrominius (with Bite, Ancient Blessing, and Ravage)
Leveling pet first, then switch to Sprite Darter. Don't let its health get down too low or you won't be able to get Life Exchange off, especially on Nitun. Keep beating it down till your Sprite Darter dies, then switch to Chrominius, who should be able to finish them off.
Ka'wi the Gorger - West of Nectarbreeze Orchard in Jade Forest. Some sort of Grub.
Abilities: Chew, Moth Balls, Super Sticky Goo
Nitun - North of the Arborteum in Jade Forest. He's a big Masked Tanuki. . He hurts, a lot, and he regens some if he kills your pet. You may need to utilize your leveling pet to finish him off.
Abilties: Prowl, Rake, Ravage
Lucky Yi- In the middle of the Heartland, Valley of the Four Winds. A large Marsh Fiddler. In my opinion, the easiest legendary pet to battle.
Abilities: Perk up, Quick Attack, Uncanny Luck.
Level 24 pet to level (make sure it goes out first) - should not be Elemental
Sprite Darter (or other Life Exchange pet - I prefer the Darters for these because they have flying abilities)
Guardian Cub (or some other pet that does high flying damage - Cub's just my favorite).
Leveling pet first, then switch to the Sprite Darter. Use Life Exchange and your flying abilities until either your Darter dies, or the pet dies. If the Darter dies first, switch to Guardian Cub to finish it off.
Dos-Ryga - Some sort of Carp or Fishy, found north of Binan Village in Kun-Lai Summit. His frost ability kind of hurts, just keep an eye on it. You'll likely need to go to your flying pet to finish him off.
Abilities: Frost Breath, Healing Wave, Whirlpool.
Skitterer Xi'a - An Aqua Strider in northern Krasarang (just south of where you'll find Greyhoof, actually). Abilities: Flurry, Skitter, Water Jet
No-No- A Sifang Otter found in Western Vale of Eternal Blossoms, right next to the wall you go over to go to Dread Wastes. His Beaver Dam ability actually stops his attacks from hitting you as well as stopping yours from hitting him.
Abilties: Beaver Dam, Dive, Tail Slap
Ti'un the Wanderer- A Spiny Terrapin found in the middle of Townlong Steppes. Keep an eye on your backline pets during this fight, as he has the only real AoE ability of all the Legendary pets.
Abilities: Pump, Shell Shield, Tidal Wave.
In my journeys on WoWhead while I was writing this blog, I also saw the suggestion that, instead of using a class-appropriate pet for your third, that you can use a pet with Predatory Strike, but I haven't tried that. I may today or tomorrow, just to see.
The first time that you do the quest for the these battles, you get a Red Panda (seen below). Isn't it cute? Then, it becomes a daily. I do the daily in tandem with my other pet battle dailies. There are three other Pandas that you can get with the daily; I've gotten two of them (twice each, too). They are still worth doing; the bag that you get at the end of the daily has the highest chance of giving you a rare upgrade stone.
How do you take down the legendary pets? Do you use my methods, or do you have your own path to victory? Share some thoughts in the comments, have a great week, and we'll see you back here next time.