Rainbow Cloud

Rainbow Dash "Rainbow Cloud"

• Rainbow Cloud was half pure   blood unicorn half pure blood pegasus, until the effects of Rainbow   Power caused Cloud to get very sick. The potion cure turned her to   become half Draconequus.
• She didn't learn that her parents were   her actually her grandparents until she moved out. Its not uncommon  for  Pegasi foals to be raised by older relatives like grandparents and  their  parents just visit while growing up. Because Windy and Bow were  so  young when they had their son and couldn't have any more children  when  the teenage Sassy Saddles wanted them to hide the fact she was  pregnant  they told everyone Rainbow Cloud was theirs
• She still  calls Bow  and Windy as Dad and Mom, this is also normal for pegasi in  her  situation. It's not uncommon for even aunts and uncles who raised a   pegasi to be called mom and dad as well as the bio parents. 
• Rainbow   Cloud unicorn magic was much stronger for a pony who appeared mostly   pegasus. This did result in random bursts of magic growing up, and the   sonic rainboom. Growing up Rainbow Cloud would often get magic surges,   and magic congestion. Rainbow has 2 sparkling scars on her front hooves   from her first Burst Up, which resulted in her pushing her magic too  far  causing the first sonic rainboom. Due to them being magic scars fur   cant grow there
• Despite being half unicorn Rainbow is still short even compare to some pure pegasi, which does help her speed.
• When   the Mane Six got rainbowfied the effects on Rainbow Cloud caused all   the magic in her to unlock. This caused it to become even more unstable   than before. She comes down with one of the worse cases of burst ups   even Queen Celestia had seen, due to her body not being able to handle   all this unlocked magic without a horn. Queen Celestia gave a potion to   help her body handle the sheer amount of magic in it. But, it turned  her  into half Draconequus.
• Rainbow Cloud pegasus type is race   peagsi which makes her wings smaller but faster, if she had tail   feathers they would be smaller than Fluttersky
• Her main physical signs of being a unicorn is her long unicorn ears and her lack of tail and ear feathers
• Rainbow has primary color braces
• Rainbow was 19 at the start of the show

Half Draconequus info

• After  Queen Celestia gave her a  potion after Rainbow Power unlocked all the  magic in Cloud which was too  much for her body. It turned her half  Draconequus.
• Despite  being an adult her control was on par to a  newborn. Discord takes her  under his wing and help teach her how to  use her magic
• She channels her magic through her antlers
• Her tail is a very large bunny tail which is very soft and Pinkie Gem often tries to use it as a pillow
• Her back paws are rabbit feet as well. Fluttersky made comments that she looks like she's part jackalope
• Even though it was a little traumatic Cloud adores her new form.