Took me 12 tries on my monk.
Here's a few of mine:
Onyxia mount dropped after a few runs, passed it because druids are BiS
After my 2nd run, was really happy about that and only recently stopped using that mount.
I've ran Kael'thas with 4 different guys. This one was the 3rd person and the first mount I've seen. Total Kael kills at this point were like 80. I passed it though. Saw another one later on, on my first run with the 4th guy. Needless to say he was quite excited as I still didn't want to mount.
http://imageshack.us/photo/my-images/16/7fbq.jpg/
Needles to say i got all 3 , TLPD + Aeonaxx + The new MoP one.
Holy shit. It actually happened!
KAra since BC evry week...
now i do it 5-7 times a week depending if i wanna do it with my non 90 toons..
never dropped
BUT on the other side LK hc mount after 6 kills lol ^^
i have screens from my mount drops.. won and lost 1,3,6, for ashes , 8 for LK hc mount my dice are all broken
love the drake
My rare collection so far, pretty small
Fiery Warhorse, took around 250 total combined kills across multiple characters for it to drop, got it on my warrior alt earlier this month.
Raven Lord, dropped off my 6th kill ever.
Grand Black War Mammoth, dropped from Koravon back in WotLK during a weekly VoA farm, probably did around 100 total kills across different chars of the bosses that drop this mount, dropped once and I won on raid roll. Got offered 8k for it (back then a lot of money!) but turned it down. :>
And the Normal Mode Madness of Deathwing mount, Blazing Drake, dropped once for us on our normal mode kills early in the tier and I won on raid roll!
http://i.imgur.com/1CTwuQu.jpg
Apart from these four not been very lucky, approaching 500 combined kills across multiple chars for Ashes of Al'ar, haven't even seen it drop let alone get it.
Your persistence of vision does not come without great sacrifice. Let go of the tangible mass of your mind, it is only an illusion. There is no escape.. For the soul burns on everlasting encapsulated within infinite time. A thousand year journey at the blink of an eye... Humanity is dust..