@Background Pony Number 17  
Chances are it may be similar to A Flight Of Dragons in that the gemstones he eats provide fuel when he digests them (a gas that is transferred to a special dragon organ that contains it) and the sparks come from his “thimble”, which was a small organ on the roof of the dragon’s mouth that produced enough electricity when stimulated to spark a flame.
 
… This also means that if he ever deep kissed someone and they kissed him back, they would run the possibility of licking said thimble.
 
Here you go.
 
Just keep in mind that the science is dated.

@Background Pony #BBFE  
Also remember that Spike was doing that to himself when trying to light the fire for the Equestria Games.

This is another reason I don’t like the episode equestria games. It was all supposed to be a buildup for Spike to actually do something in front of the crystal ponies to justify his hero status, and when he did his big “breathe fire to fix a problem”, his fire was boring orange instead of the Green it normally is.

@Background Pony Number 17  
I think organic

Judging from the sparks, I’m guessing Spike has flint tonsils. I wonder if they’re organic or if he has to swallow them the way some birds will swallow stones to keep in their crops and aid in grinding their food?

@Background Pony #E5A5  
I like Spike as well. Wasnmt lookin’ for trouble

@Background Pony #E5A5  
I’m not, but some others are possibly. I like Spike, don’t get me wrong though.
 
@Background Pony #A3A6  
This stuff?

@Background Pony #BBFE
 
He’s clearly happy to be helping—that’s why he’s there. There was no cause for drama,and none would have happened. Please don’t go looking for trouble where there isn’t any.

@Background Pony #BBFE  
@Ltmajordude  
None of you know what the “Spike Justice Warriors” thing is usually about, right?

Eh, strikes me as being akin to the “minigun Twilight” gag from Season 2.

@Background Pony #BBFE  
Unless he had another method of lighting the logs and the lighter method wasn’t on his mind, though it was on Applejack’s mind.
 
Just saying. Just in case that’s an excuse those “Spike Justice Warriors” will bring up. I noticed that he was smiling as well.

Before the “Spike Justice Warriors” freak out, note that he’s smiling before he does his “lighter” impression. He’s not being “harmed/abused,” he’s willingly helping Applejack with his fire.

love this