This comments section… Is full of headcanon fuel!  

@Blood Brandy  
The tag is oc:Griffon wife

So Ponies consume products of the life in the world, creating nonliving matter. Dragons consume the inedible matter and purge it of pollutants and chemicals, leaving it revitalized for life.  
I like that sort of idea.

@Lawful Girly  
I thought he meant Greta

“Back off old-timer, this is cool stuff!”

Cigars may be good for dragons, but the smoke they produce is toxic for ponies, and most mammals.

Oh I get it! It’s like Bender with the alcohol!

@Trahzo  
She’s pretty cute.

Cigarettes may be fine for you, Spike, but for ponies? Not so much. You should vape instead.

“Cigarettes are my vegetable.”  

@Lawful Girly  
Another OC.

@Trahzo  
Wait, you mean Gilda as griffon waifu, or another OC?

@Trahzo  
I’d like that.

@Trahzo  

Um…we got horse wife and griffin wife…is she going to be dragon wife?

@SquiggyBomb
 
That argument doesn’t work so well when you consider the fact that humans have a massive resistance to things that easily kill many other animals, such as theobromine.

@Background Pony Number 17  
And yet he can still eat flowers. I just assume that dragons are like furnaces inside, they just need any type of fuel.

Well, most myths about dragons say even non-fire-breathing ones have poisonous breath, and dragon blood supposedly has all kinds of freaky magical properties. So yeah, Spike’s probably immune to most things that can kill a pony, and probably considers them essential nutrients.

He has a belly full of fire and can survive skinny dipping in LITERA lava. A little nicotine isn’t do hurt him.

Headcanon accepted.

well this is a good point, dragons swim in lava and eat crystals so all the tar and poison in cigs would maybe even be good for them.

Heh, well played, random dragon hippy store owner.

Give him back his health cigs, Twilight! Are you trying to kill him!?

Mmmmm that Arsenic is making me hungry.

@FanOfMostEverything  
Maybe he IS? Maybe that’s why dragons don’t get hurt in lava, because they’re silicon-based lifeforms. :O