Super-Turtle
From superman.nu: Supermanica
Super-Turtle
The super-powered chelonian who shares many of the powers and some of the wardrobe items of Superman.
In a text for June 1966, Superboy enlists Super-Turtle as a temporary replacement, enabling the Boy of Steel to take a short vacation (SB No. 130: "Substitute Superboy").
In December 1967, when Super-Turtle's super-hearing picks up someone in distress, he runs to a nearby telephone booth in order to change into his Super-Turtle costume, only to find someone already there --that person ends up being none other than the Man of Tomorrow himself, Superman! (Act No. 357)