Artist’s description:
 
“-Derpy’s real name is Derby Hooves.  
-After a traumatic incident in her youth, Derby began to suffer from strabismus, giving her her signature weird eyes.  
-She used to be a great flyer, winning several junior racing leagues until the accident. Afterward, she could barely fly in a straight line, and soon fell out of the racing scene altogether.  
-Following the accident, and coupled with her new awkwardness, ponies began to call her Derpy instead of Derby, and she was too polite to correct them, so the nickname stuck, eventually becoming such a commonly spoken moniker that it was used by practically everyone.  
-Derpy moved from Cloudsdale to Ponyville as a teen, taking a postal job when she realized that she had to make a living, and lacking fine motor skills, there weren’t many ponies willing to hire her.  
-Despite initial setbacks and some doubt on the part of her employers, Derpy soon proved to be a decent postal pony (although initially she kept sending mail to the wrong homes and licking the stamps when she believed that nopony was watching). Her can-do attitude and bubbly personality helped her stay employed after the first few weeks. Despite her drawbacks, she was very good at being on time, and most ponies had only good things to say about her service.
 
-Derpy’s cutie mark symbolizes her bubbly, cheerful personality. She likes to be silly and lighthearted, even when it sometimes comes off as annoying to others.  
-Her love of muffins came from her childhood. After her life-changing accident, her mother made her muffins to make her feel better. She loves all sorts, but her favorites are banana nut and blueberry.  
-Even though she is no longer able to race, Derpy still enjoys competitive sports.  
-She is good friends with Bulk Biceps, another disabled pony. Their combined enthusiasm is known to leave some ponies temporarily deaf”