Twilight Whelpling
Source: Pet Battle. A re-emergence of whelps outside of Grim Batol has the red dragonflight worried -- something is happening in the lost city. Dragonkin type. is a new wild battle pet in 8.2. This pet can be found in the Cataclysm zone Twilight Highlands, around the entrance to the dungeon, Grim Batol.
The Twilight Whelpling is a wild battle pet found in Twilight Highlands near the entrance to Grim Batol dungeon, captured directly from the wild.
Guide awaiting review
Travel to Twilight Highlands
Head to Twilight Highlands and look for Twilight Whelplings near the entrance to Grim Batol. Multiple pets can be found up at the same time.
Battle and capture the whelpling
A reliable team for capturing is a Warbot: open with Minefield, then use Missile until the Twilight Whelpling is low enough to capture. Two Nexus Whelplings can handle any remaining pets in the encounter.
Upgrade with a Battle-Stone
Twilight Whelplings only spawn at Uncommon quality, so use a 
Flawless Dragonkin Battle-Stone to upgrade yours to Rare. Observed breeds include H/P, P/S, and P/B.
Complete the introductory quest
Capturing your first Twilight Whelpling unlocks the quest 
Young Twilight Scale — complete it to progress the associated reward chain.
Note the pet is not cageable
Because the Twilight Whelpling is a wild pet, it cannot be caged and is therefore not available for trade or purchase on the Auction House.
Tips
The Twilight Whelpling shares abilities with the Twilight Clutch-Sister, making it a strong and far more accessible alternative for Legendary pet battles.
