Judging from the pets coming in 7.1, it looks like this is finally coming up. First, the obvious ones:
Ironbound Proto-Whelp: Razorscale
Snobold Runt: Beasts of Northrend
Winter Rageling: Hodir
Nerubian Swarmer: Anub'arak
Runeforged Servitor: Iron Council
Igneous Flameling: Ignis
Creeping Tentacle: Gonna go out on a limb here and guess Yogg.
Boneshard: Almost certainly a Lil' Marrowgar
Some others have less obvious bosses.
G0-R41-0N Ultratonk: Probably Mimiron, could be Flame Leviathan or XT though.
Blightbreath: Probably a mini Festergut, could be from Putricide or any boss in the plague wing.
Blood Boil: Possibly Deathbringer Saurfang, could be from Blood Queen too.
Soulbroken Whelpling: Probably Sindragosa, but could be Valithria.
Some may or may not even be in there:
Sanctum Cub: Auriaya?
Snaplasher: Freya?
Stardust: Algalon?
Squire/Gruntling: Faction Champs?
Dreadmaw: ???
Drudge Ghoul and Wicked Soul both feel like Arthas drops, but if precedent holds, there can be only one. Wicked Soul might be the meta reward.
What's everyone else think?