Ratcatcher

Otis Flannegan (a.k.a. The Ratcatcher) is a villain from the Batman series. He started out as an actual Ratcatcher, but he soon found out he had the ability to control the rats. He then started using them for his criminal purposes.

Batman: Arkham Asylum
The Ratcatcher doesn't appear in the game Batman: Arkham Asylum. One of the Riddler's riddles revolves around him.

He has an entry in the Character bios. His profile states:

Once employed as an actual rat catcher in Gotham, Otis Flannegan soon started using his natural gift – an affinity with and ability to control rats – to stage a variety of crimes. Eventually his control over the vermin grew until he threatened Gotham City with a veritable army of rodents. Incarcerated many times at Blackgate, he’s able to do as much damage within prison as without, using his loyal pets to relay messages and transport materials inside the maze of ventilation ducts that wind throughout the giant prison.

Facts:
Real Name: Otis Flannegan

Occupation: Professional Criminal

Base of Operations: Gotham City

Eyes: Blue

Hair: Brown

Height: 5 ft 11 in

Weight: 155 lb

First Appearance: Detective Comics #585 (April, 1988)

Attributes

 * Thorough knowledge of Gotham's sewer system and Blackgate Prison's layout
 * Eerie ability to wordlessly communicate with and command all rats
 * Overvalues rodent life, especially in comparison to human life