https://www.polygon.com/2018/5/31/17414074/lunastra-monster-hunter-world-update-4-0-arch-tempered

Lunastra — a blue, lion-like Elder Dragon — has arrived in Monster Hunter: World. For those unfamiliar with the returning beast, Lunastra is the mate of Teostra, and packs just as much of a fiery punch as her male counterpart.

While Teostra has been in the game since launch, Lunastra is just now making her Monster Hunter: World debut, having most recently appeared in Monster Hunter: Frontier Z in Japan in 2016 and Monster Hunter: Freedom Unite worldwide in 2009. Now that this power couple is in-game together, they can pair up for a powerful attack against over-eager hunters. If you plan on trying to take these two out together, be careful when they start to tangle together — this isn’t the turf war mechanic you’re used to seeing, and will instead result in a deadly explosion.