I'd Like to start with saying I tried searching and did my best and I didn't find any post about this.
First of you will Need the quest in Grizzly Hills (The Thane of Voldrune - Quest - World of Warcraft), Wich allows you to mount on the proto-drake "Flamebringer".
Then all you will have to do is mount up on your ground mount and speak with "Flamebringer" To Ride a Proto-drake.
now you got your self a Ground mount, mounten on a flying mount.
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