Derpy IS her canon name! Only fans call her Derpy. In official storyboards she is called Derpy. Her filenames on the hub site refer to her as Derpy too. No offense meant, but people who think her name is Ditzy clearly have spent no time actually checking that out. Ditzy is some other pegasus. Hopefully all this can be settled once Derpy gets her own episode, I am tired of this mistake.