April O'Neil (clones) (2012 TV series)

April Clones are clones of April but need April's DNA for complete. Most of the April clones turn into black slime once killed. Reject clones are mostly deformed, disgusting, prototypes like April Derp

History
One April clone has easily fooled the turtles into trapping them into a detention cell. She proceeds to attack them. Donnie realizing the April was a fake, manages to defeat her before turning into black slime. Soon the turtles figure out that there are tons of April clones settling in mutagen. The Kraang soon finds the turtles and sets a rejected April clone (soon named April Derp) free. April Derp attacks the turtles while the real April's DNA was about to be extracted. April set out a large energy blast killing April Derp. Not long after, the incased April clones were set free attempting to fool the turtles. They pull April into the crowd until April pulls out her tessen, and proceeds to kill 2 April Clones. Realizing that's April the Turtles pull out their weapons and kill the remaining April Clones.