“Fluffy but not chubby.”  
 
The other reason why I didn’t want to draw Twilight is, uh, you know I like merging creatures together, as for Twilight…I mixed puppy into her. So actually she’s half pony half puppy, the puppy specie is Pomeranian, small round and fluffy.  
 
So why I call her “Chihuahua”? Because like Chihuahua, smallest (of the mane six), super jealous, sometimes grumpy, very smart, glue to her horsebando.  
 
Everyday when she wakes up, it takes her at least one hour to groom her fur and mane and wings, and sometimes she’s fed up with her fur, she cut it off simply, but it will grow fully tomorrow. She doesn’t like anger, cause when she’s angry, her fur her mane will puff up and it will take her one hour to groom her fur.  
 
By the way, she doesn’t like anyone messing with or caressing her fur.  
 
Fluffy Twilight headcanon is mine.