I got 2 Snobold Runts in 6 runs last night, one Nerubian Swarmer, and one more Dreadmaw, so I now have three total.
I didn't run any other instances, I was simply going for the Snobold Runt and Nerubian Swarmer from ToC as I've badly hurt my back and can't focus on moving through an instance between fights due to painkillers. Tank and Spank in a round room is about all I can do at the moment.
Edit: I ran it on all combinations of normal, heroic, 10 and 25 man, I didn't keep track, I ran it on the highest difficulty I thought each toon could handle, I do know that the first Snobold Runt dropped on 10 normal, as did the Nerubian Swarmer, so I don't think difficulty has any bearing on drop rate.
Thaliana#1794 - My WoW account has 50 toons, so I would so greatly appreciate people creating toons on Kael'Thas or Ghostlands to trade with me. <3