Dungeons:
Culling of Stratholme
Hellfire Ramparts
Blood Furnace
A Dire Maul wing
Magisters Terrace
Shadow Lab
The Botanica has a demon
The Arcatraz
Mechanar
Violet Hold
Well of Eternity
Raids:
Karazhan
Hyjal Summit
Trial of the Grand Crusader
Magtheridon's lair
Black Temple
Sunwell
Well those are all the ones that come to mind with at least one demon in them(counting satyrs as demons but not officially sure if they count though.)
You killed a dragon in all but 1 raid (ToC) in WotLK and 3 of those raids were centered around killing that dragon. Hell, they even retuned Onyxia during that time, so if you want to count her, that's 4 raids. To be honest, facing dragons wasn't really that epic when Cata rolled around.
Soothing Mist:"Healing them for a minor amount every 0.5 sec, until you take any other action."
Jade Serpent Statue: "The statue will also begin casting Soothing Mist on your target. healing for 50% as much as yours. "
[What's half of minor?]
"Statue casts Soothing Mist at a nearby ally for toddler healing."
Soothing Mist:"Healing them for a minor amount every 0.5 sec, until you take any other action."
Jade Serpent Statue: "The statue will also begin casting Soothing Mist on your target. healing for 50% as much as yours. "
[What's half of minor?]
"Statue casts Soothing Mist at a nearby ally for toddler healing."
Fact (because I say so): TBC > Cata > Legion > ShaLa > MoP > DF > BfA > WoD = WotLK
My pet collection --> http://www.warcraftpets.com/collection/FuxieDK/