Gunther Hardwicke is part of the team of thieves known as The Terrible Trio. He later adopt the alias Sherman Shackley and wear the mask of a shark. Originally The Terrible Trio were famous inventors in Gotham City, boring rich men seeking thrills and challenges so they became a criminal band, imposing challenges to the dynamic duo. They wear business suits and masks of animals, they created their technology devices according their respective animal themes. Shark specializes in water or underwater devices, especially in submarines.
Due to a possibly history of drug abuse he suffers a mental breakdown, thus Sherman trying to reinvent himself faking his own death and attempts to murder his partners. He is stopped by Batman. Shackley is killed in a prison stabbing which was orchestrated by his former comrades and their newly elected member...White Shark.
Bruce confirms Shackley's death when he comes up against a new generation of the Terrible Trio. This new Terrible Trio consists of Timothy Fox, the fallen son of Lucius Fox and two of his miscreant friends. The troubling thing about this new Terrible Trio is that they are being financed by Talia al Ghul.
In other media
Batman: the Brave and the Bold:
He appears in eleventh episode of the series. He is shown as a boring millionare seeking for thrills. Along with Fox and Vulture, tries to kill their master Wong Fei so they can get the Wudang Tottem in order to invade Hong Kong. Using the powers of the totem, he transforms in a shark humanoid. He is beaten by Bronze Tiger.
He uses a massive hammer as weapon. He is a voiceless character.