OC and image are not mine!
 
From image source (slightly edited):
 
Name : Mockingbird Dash
 
Nicknames : Mocky / Mock / Mocking / Dash Jr
 
Place of birth : Cloudsdale
 
Place of residence : Cloudsdale
 
Parents : Rainbow Dash / Dumbell
 
Facts and Bio : Mockingbird is the first child of Rainbow Dash and Dumbell, she’s very proud to be the daughter of one of the greatest wonderbolts, she started flying a few weeks after she was born, which is very rare since she didn’t had the suitable wings, she still had the baby feathers.  
Rainbow Dash always expressed her pride to have a strong flyer as her daughter, Mocky’s name was originally Thunder Dash, but as she grew older she changed her first name as a joke, but she decided to keep it that way.  
She entered the wonderbolt academy not long ago and stands out from the rest both because of her unique flying skills, and, because of her bad behavior, she tends to tease other ponies too much and that is not appreciated by Spitfire.
 
-Her bandages are not there for a particular reason, she just likes to have something on her front legs  
-She’s got two piercings on her left ear  
-Her mane covers her right eye for aesthetic reasons, she uses her flying glasses to put it aside and be able to see while she flies.