Nanaue, better known as King Shark, is a shark-like serial killer/cannibalistic criminal and a member of the Suicide Squad.
Around the time Amanda Waller gave the order to call in the Suicide Squad, a police squad managed to arrive at the Palms Hotel where King Shark was at, who was bathing in blood from his victims (who were hanging on the ceiling akin to a meat rack). He managed to toss them out of the room and lunge after them, although he somehow ended up subdued by them.
He then came to inside the Suicide Squad headquarters, and tried to eat Killer Frost (who herself was recruited after a failed bank robbery), only for her to quickly subdue him, leaving him impressed. He also demonstrated a fear of heights when being airdropped into Gotham.
After meeting with Penguin for a means to infiltrate Arkham Asylum, King Shark infiltrated the area via the sewers, also killing a security guard before bringing up a duffel bag. After a gas explosion that sent the asylum into yellow alert, King Shark gave the idea of switching the security footage in an attempt to keep Batman off the mark, although it failed due to failing to take into account the day the video was made.
He later ended up, due to his lack of subtlety, causing a fight in the Exercise Yard. He later fought Batman when he arrived at the evidence locker, also giving Batman a difficult time, although he ended up subdued by a electrical press being forced against his groin by Batman, eventually being forced to flee when the evidence locker began to collapse due to damage sustained from the fight.
Later, he tried to aid the other members of the Suicide Squad in getting to the Electroshock therapy room to disable the bombs on their necks. However, due to his fear of heights, King Shark needed to be blindfolded and guided to the door.
Ultimately, the electroshock therapy did not save him, because his skin was too thick for the electricity to actually short out the bomb.