@QueenCold  
Because this whole thing, with the ponies being enslaved and menaced by yaying apples was the funniest thing Spike had seen in years.
 
One day when he’s an old, old dragon, he will remember this and die laughing.

Yes, Pinkiebat is canon!

 
“Pinkie Pie is my pony!”

@Background Pony #2B7E  
At the same time, though, you could argue all winged creatures have the magic that allows them to stand on clouds…
 
Except maybe Bats, not sure on that one

@Blood Brandy  
I’m pretty sure that during the “may the best pet win” song, several winged animals in Fluttershy’s home were standing on clouds too. It seems to be that in Equestria, all winged creatures can stand on clouds.
 
Good news for Spike if he ever does grow wings by maturing normally, I guess.

@Stotter  
If you mean the Animal Planet one, I think that was more assuming a world without magic, specifically our world as we know it. Spike is in a magic world, with magic ponies and was himself hatched with magic. That said, opening his ‘inbox’ would still imply he has some sort of magic storage system, since sent things won’t stay in transit, and seem to have to be ‘received’, like when Celestia sent them back en-masse during Discord’s first release. That said this could be seen as something like over-stuffing the ‘Inbox’, as Spike was pained by it, but even then that would denote some sort of internal magic storage of some sort.
 
And if it were the scrolls that were enchanted, there have been times, specifically in ‘Griffon the Brush Off’, where a number of seemingly normal scrolls and paperwork, directly from town hall, were burned and sent to Celestia, despite the fact the Mayor, and seemingly most if not all her aides, are earth ponies and such paperwork would have no reason to be enchanted.

@Blood Brandy  
He sent it to himself, then opened his inbox? I admit that part of the scene you mentioned is a headscratcher. Putting that aside for now, I’d like to mention that Discovery Channel had that mockumentary with a biological interpretation of fire-breathing for dragons.

@Trahzo  

 
I wonder if this is what the Everfree monsters say about the ponies?

@Millennial Dan  
Come-on, they’re sentient food, they’ll get eaten one way or another or just spoil.

@Trahzo  
I don’t think it works like that.

@Millennial Dan  
Since they’re food, it doesn’t count.

Apple murder?

@Stotter  
That would still raise the question of his ‘Fire Storage” that he pulled the card from during ‘Spike at Your Service’, where he belched up a card of his own creation. I doubt he would have Celestia on standby to send the card at just the right time.
 
I think the better explanation might be either Tirek doesn’t drain non-ponies (He only went on about pony magic, and there are other creatures seen, specifically Spike and the Buffalo near Appleooosa, that seem unaffected, Discord being an exception due to being Discord), Tirek can’t drain non-pony magic (Same reasons above, with Discord being an exception due to being part pony) or he is only able to drain one brand of magic at a time (Pony, dragon, etc.), and disregarded Spike (And, by and large, numerous other creatures) as not being worth it.
 
Personally, I prefer the last one because I am of the belief that Magic is a more intrinsic thing to a Dragon, probably being needed for a lot of the things they do (Strength, resiliance, fire, etc), and given how badly the magic drain effected Ponies, it might be more difficult and more deadly on Dragons, making it more time consuming and he was in a bit of a rush to find Twilight.
 
And before someone thinks non-ponies don’t have magic, it would be the only explanation for some things, like Griffins being able to stand on clouds (It has to be something in the Griffins, because if it were a property of the clouds, Twilight and Co. wouldn’t need a cloud-walking spell in Cloudsdale)

@Ardashir  
Or the clone execution orgy.

Odd question time – is it implied that the Vamponies actually killed the apples they drained, or not? I mean, I seriously doubt it for this comic but given that they look dead. That and being pieces of fruit may let them slip past the ‘no killing’ rule, like how they used to brutally destroy Scarface on Batman TAS.

@Background Pony #C197  
I guess I should have clarified that it’s reaching to call Spike’s strength magical.

@Stotter so what did tirek take, applesauce?

@Trahzo  
It’s reaching to call that strength magical.

@Stotter  
Since Spike has the strength to lift huge ass books, Tirek probably took his strength just like the earth ponies.

@Blood Brandy  
Dragons do not have magic to drain. Explanations for fire-breathing aside, despite earlier assumptions of how letter teleportation works, it’s clear that the scrolls themselves are enchanted to teleport when burned. Everything else he breathed fire on just burned or melted.

@Blood Brandy  
He would still get Yamcha’d by Tirek!

@Trahzo  
By the time they were in the cage, Discord was drained already

@Background Pony #DEBB  
That could be based on a number of things. A. the cage was conjured and could be magical, and therefore something he couldn’t damage, B. He wouldn’t want to leave his friends behind when they were too weak to move much (Although, I still wonder if there was a reason Spike didn’t seem to get drained, seeing as how his eyes didn’t get greyed) or C. Escaping might not have done any good if Tirek just teleported them into the magic bubbles.

@Background Pony #DEBB  
I think the reason for that was, if he did chew through the metal bars and got out of the cage, he’d be Super Yamcha’d by fucking Discord & Tirek!

@Blood Brandy
 
@QueenCold
 
He didn’t eat his way out of the cage in Twilight’s Kingdom part 2.