Normally, a Broodmate dragon does the same thing as an eagle and decides to share territory with their mate to rear children. This set of them has decided to share territory without the prospect of children. Better hunting, more security, or perhaps less chance of other males looking to fight for territory against two females holding their on on the Jund-Naya border jungle highlands... who knows?
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Went with two changes. Jund dragons are akin to savage cavemen when compared to other dragons, so I made them just a bit more primitive and tribal rather than outright feral and monstrous.
Second change, that godawful face on the Broodmate Dragon.
That is not a mug you wanna chug. So I took a sledgehammer to the extra complex coral lookin' design and just went with the look of many of the other Jund dragons(specifically Predator Dragon, Hellkite Overlord, and Flameblast Dragon) with some motifs of the Broodmate thrown in.