Shredder Clone

The Shredder Elite were a group of three entities that lived in Foot Clan Headquarters. Though their exact origins are a mystery, it is obvious that they are hideously mutated ninja that wear apparel similiar to The Shredder. The Shredder Elite consist of a large, four-armed Shredder (known as Multi-Arm Shredder in toy form, and Shiva Shredder on 4Kids' website), one with large, monstrous crustacean-like claws (known as Claw Shredder in toy form, and Spike-Armed Shredder on 4Kids' website), and a diminutive Shredder with a single, long wrist blade on each arm (called Tiny Shredder on 4Kids' website).

Mirage Comics
The Shredder Elite first appeared near the end of Teenage Mutant Ninja Turtles #20, "Return to New York, Part 2". They murder the Triceraton soldier Zog as he is walking through the entrance to their abode. The Turtles battle them in the next issue, and during the brawl, the four-armed Shredder Elite loses an arm, which to the Turtles' surprise, seems to be exuding earthworms.

Shredder later elaborates briefly on the Shredder Elite's origin; using a blend of ancient magic and modern science, Foot scientists have trained a species of colony worm to feed on the remains of a person, and form together to become a replicate of said person. Shredder goes on to indicate that the Shredder Elite were experimental subjects, and on the four instance, they were fed Oroku Saki's charred remains. However, nothing is revealed of whose remains the worms were fed to create the Shredder Elite, nor is it mentioned why they have donned The Shredder's outfit.

2003 series
Introduced at the end of Episode 21, "Return to New York, Part 1", the Shredder Elite are seen in liquid-filled vats deep within Foot Headquarters. The Shredder Elite are released when an alarm goes off shortly after the Turtles and Splinter arrive. In the following episode, The Turtles and Splinter battle them. Their appearance has changed slightly to more closely resemble this universe's version of The Shredder, and the "Claw Shredder"'s claws are less crustacean-like in appearance.