This is s direct follow-up to the previous original species drawing that I've made recently.

The creature presented above is neither a subspecies nor even a variant of the Runner-Drake. It's a mutation.
Through yet unknown and not understood means, certain males of this species undergo a drastic transformation: they become larger and bulkier than their contemporaries, losing, at the same time, some of their nimbleness and agility. They are also capable of producing more potent slime in their cheek organs.
Scholars have noted that packs lead by what is dubbed an Alpha Arid Runner Drake often increase their numbers beyond their usual capacity and also start hunting larger prey. This is in no small part thanks to their leader. While the smaller drakes run down and harass the prey animal, the Alpha swoops in to deliver the killing blow.
After that, the Alpha guards the kill allowing his subordinates to feed in peace. In return for providing his pack with food and protection from other carnivores, he gains the right to breed with all the females in the pack. By animal standards, a fair tradeoff.

More research needs to be conducted...