Tiny is the giant great white shark kept by the Penguin in the "Torture Chamber" of his museum, the Cyrus Pinkney's Institute for Natural History.
Batman: Arkham City
Tiny swam around in the tank at the former Terrors of the Deep exhibit at Cyrus Pinkney's Institute for Natural History, which has been repurposed into the torture chamber for the Penguin's base. He fed on anything that entered the tank's water. When Batman was hunting for Mr. Freeze within the museum, the Penguin left three undercover cops on the frozen-over surface of the torture chamber to die of hypothermia and then be eaten by Tiny.
Batman saved the undercover cops, and went on to rescue Mr. Freeze, taking a disruptor from Freeze's suit that would disable his Freeze Cannon, which was currently being utilized by The Penguin. On his way to the Iceberg Lounge, Tiny attacks the Dark Knight for getting too close, but Batman beats the shark down, and Tiny is never to be seen again after the encounter.
Batman: Arkham Knight
Tiny is seen again during the GCPD Lockdown DLC story. Penguin has apparently had him moved to a large tank near his base of operations in a Bludhaven dockyard. He can be seen facing the glass as Nightwing begins fighting off goons before swimming away. If Nightwing approaches the tank after the fight, Tiny will ram the glass with enough force to crack it before retreating again. He cannot be seen again after this.
A shark corpse with a similar model to Tiny can be found hung up beside the Falcone Shipping Antenna in the Cauldron neighbourhood of Bleake Island. It has a massive hook sticking out of his jaw, seemingly having been fished out in this location.
- Enemy chatter implied that Ratcatcher was fed to Tiny after Penguin's initial attempt of executing him by having him being devoured by rats failed due to their being bored of him.