She of course is one of the more popular characters in MLP Friendship is Magic mainly from her crossed-eyed form. She originally wasn't ment to be crossed-eyed when she appeared in the first My Little Pony episode. It was actually by accident when she had her crossed-eyes and her face wasn't even ment to show on the screen. When the cross-eyes were added they had been added only by accident and thats when fans saw her in the background and she then became one of the most popular characters in the show.
Derpy's original name was ment to be Ditzy Doo, but fans (who didnt know it) began to call her Derpy instead. But instead of keeping it at Ditzy Doo, they decided to choose the popular fan name Derpy and it became her official name as "Derpy Hooves". As the name was now official to be "Dery Hooves" her first name was mentioned by Rainbow Dash in one of the episodes. But in that episode her name was still ment to be Ditzy Doo but to make the fans of MLP happy, they changed it to Derpy Hooves. Derpy is one of few background characters with a official name, as it of course is because of her general popurality on My Little Pony Friendship is Magic. Derpy has also been given nicknames before her name was chosen as Ditzy Doo and then later Derpy Hooves, the following nicknames are listed here: Stoneface, Bubbles, Bubblehead, and her original name Ditzy Doo.