April Derp is a corrupted version of April O' Neil.
Created from the DNA of April O’Neil herself, April Derp is a monstrous version of the original. A clone “reject,” this hideous, hulking tool of the Kraang has two heads (one tiny and one large), along with super-strength and endurance! Her very limited intelligence, however, is demonstrated by the single word she has in her vocabulary—“Derp!”
Her first and final appearance was in the episode, "The Kraang Conspiracy". She was a reject clone (a genetic mishap) of April made by The Kraang. She attacked the Turtles, but was soon killed due to April's telepathic powers. She was last seen exploding into a huge pile of black goo...
- On April Derp's right eye, there is a tiny head that resembles that of the real April O'Neil.
- In her promo picture, her left arm and right leg are horribly deformed. However, in The Kraang Conspiracy, it was the other way around.