In the 2003 TMNT series, the Shredder is a red alien Utrom named Ch'rell, who utilized an indestructible exo-suit to disguise himself as a human named Oroku Saki.

How did Shredder get mutated?

After fully recovered from his recuperation, in the episode City at War, Oroku Saki has become a Super Mutant known as Super Shredder. As Super Shredder, Saki went onto kill his nemesis once and for all, finally obtaining his long awaited vengeance.

What happened to Shredder TMNT 2003?

The Shredder was defeated after Zog sacrificed his life to keep him on his freighter when it exploded, but Karai rescued him on a helicopter. The Shredder had survived once again.