Took me about 15 kills
>.>
To be fair its probably the RNG gods making up for the fact I ran heroic shattered halls back in BC a good 40-50 times, and swear to god, never saw my dungeon set gloves drop even once.
Took me about 15 kills as well. That's ignoring the 15 I probably ran it in the past, I suppose, when the content was still current. Still, that's not bad. Everyone is going to get their lucky drops while also having some stuff that's very unlucky.
Sea Turtle - Got on my second or third cast into a pool on this character.
Onyxian Drake - Took 10 kills on this character (and only about 12 total across all)
Fiery Warhorse (Kara mount) - Took seven or eight kills (15 total across all)
Green Proto Drake - Maybe 10 eggs?
And then some of my unlucky drops?
Vitreous - Hit 180 Slabhide kills and still nothing.
Old Cranky/Ironjaw - I've caught them twice each and all four took me over 1,000 casts each.
Headless Horseman mount - Everyone flies around on this guy and I never get him to drop each year.
I'm still waiting on ZG mounts, Blue Drake (one of two mounts from Malygos), Ashes of A'lar, Alysrazor mount, and plenty of others. I run those listed right there all weekly. Slabhide I run around four times a day on average.
I find the best way to not get annoyed about rare drops is to not click the corpse expecting to see the corpse but instead get into a rote routine and then when the mount does arrive it'll be a great surprise and you'll feel fantastic. Takes away weekly disappointment and in its place gives you occasional surprises instead of relief that doesn't make up for the months/years of trying for specific mounts.
Or at least that's how I go about it.