A twin-headed monstrosity, the Ashenvale Chimaera is one of the rare mounts added in the Battle for Azeroth. Although, it uses the same model as the Draenor Rylak, except for the different coloring, coupled with some original flight animations, like barrel-rolls etc.
The Ashenvale Chimaera can be obtained in Darkshore from a Rare-elite monster – Alash'anir, who is a chimaera himself and can be found at 56.6 30.8. Moreover, it is worth noting that the mount can drop regardless of which faction controls Darkshore at the time. However, it is not a guaranteed drop, the chances seem to be around 5 per cent, so not only is the mob rare, so is the drop; as such it may take a long time and numerous tries to finally get this wonderful mount.