Lady Shredder was a character of unknown identity, that appeared toward the end of the Image run of TMNT comics. After Raphael fought Pimiko, the daughter of The Shredder as she attempted to wrest control of the Foot Clan from him, a female clad in Shredder armor appeared. Raphael, thinking it was Pimiko, conceded that she had proven herself worthy of taking back the clan, but he then saw her, complaining about an injury she suffered during the fight.
Lady Shredder then chained up Raphael, forcing him to join her rule of the Foot, or die. The other Turtles arrive and free him, and the four of them along with Pimiko battle Lady Shredder and the Foot.
Series had ended before Lady Shredder's identity could be revealed. A note in the comic's letters pages indicated that it was intended to be Karai, but it is resulted that she was Headhunter/The Mistress, the sister of the late Tang Shen and Shredder's consort.
1997 TV series
2003 TV series
2012 TV series
Rise of the TMNT
TMNT: Out of the Shadows
Batman vs. TMNT