@Starswirl  
I’m gonna stick by “Book Lung” because it’s an amusingly silly name.

So she never did get a widespread fan name?

All he needs now is a sniper rifle and some camo.

@soundtea  
My bad, only seen the episode once, so I may not remember certain things super-right. This was the one who stood out in my mind for whatever reason (probably being a different color), so I mistakenly remembered him as the one with the name I guess.
 
@Softy
 
I have a couple other suggestions: Chelicera (spiders use those to injected venom, and “venom” is also sometimes used to refer to hatred, which he incited against Starlight) and Imaginal (after the imaginal disc and because Twilight made him up).

@Scrounge  
Cornicle was the one that yelled ATTACK.
 
EDIT: Wait, Cornicle was the reddish eyed blue one.

@Softy  
Since Twilight made him up, how about Book Lung?
 
EDIT: Wait, are you sure this isn’t Cornicle?

@Softy  
I mean, it’s what the fandoms been doing, at least the show is consistent with us for once. xD

@Blissey1
 
Headcanon accepted.

my personal headcanon is that changeling can’t spot eachother unless they’re specifically trying to detect one another.

@JP  
Thorax managed to fool Chrysalis. Thorax needed to slip up before Chrysalis noticed.

So anybody else find it weird that imaginary traitor changedling looks sort of Applejack like? Orange with freckles anyways…

@Masque Raccoon  
Weird, other Changelings especially the Queen should be able to sense it.

@Softy  
Honestly, since most of them look the same I don’think Cornicle will be getting much attention.

@PonyPon
 
@Softy
 
@gingerninja666
 
Right, she didn’t catch it until he let his disguise falter for a moment. Otherwise, she was completely oblivious.

Also this guy needs a name.
 
(And is the other changeling’s name canon? It was Cornicle. Apparently all changelings are named after body parts.)

He’s got freckles.

@PonyPon
 
It wasn’t instinctive though. She almost missed it.

@PonyPon  
She did, but it took her a minute, and it seemed to be because Thorax’s disguise faltered just a bit out of fear (His eyes flashed blue, the color of his magic.)

@Masque Raccoon  
I thought she did.

@JP
 
Chrysalis didn’t even recognize Thorax when he was shapeshifted into Starlight.

@JP  
It seems to be a common headcanon that changelings can recognize each other… which doesn’t really work since it was proven false in their very first appearance when Fluttershy was able to fool a group of them into thinking she was a changeling.

@JP  
Well, Twilight probably just don’t know that much about changelings…

Do changelings not recognize the “pony” before them is a changeling in disguise? You think recognizing their own, even when disguised, would be really important for their own survival.

He still looks a bit ratty, doesn’t he?