The Nadurni gene manipulator was a gene manipulator created by the Nadurni.
The Nadurni used their gene manipulator to turn several animals or humans and animals into one single creature, a warrior. They kidnapped many humans and turned them into a creature between animal and human, for example Father Carrass and Oliver Blazington.
They also wanted to use the machine on the Eleventh Doctor to turn him into a monster that would fight for them. They wanted to create a warrior who could cheat death. However the Doctor was saved by Oliver Blazington, who got stuck in the machine instead.
The gene manipulator was used for a second time on Oliver Blazington. He turned into a monster who's only mission was to hunt. He started with the Nadurni.
Then Doctor turned the other creatures back into their real selves, by using a teleportation machine and connecting it to some cables. The molecules of the creatures started to divide and formed the outlines of two separate animals or humans. He told Amy and Rory that if they could be put together they could also turned apart.
After this the Doctor teleported the creatures home.