* The Joker in Batman: Arkham Asylum, Batman: Arkham City, and Batman: Arkham Knight.
* The Penguin in Batman: Arkham City and Batman: Arkham Knight.
* The Riddler in Batman: Arkham City.
However, he also has some credits for television and film projects:
Television
* The Venture Bros. (2003-2023) - Various voices
* The Oblongs (2001-2002) - Additional voices
* Gary the Rat (1995) - Various voices
* The Tick (1994-1995) - Various voices
Film
* Batman: Arkham Origins (2013) - Voice of The Joker
* Batman: Arkham Knight (2015) - Voice of The Joker and The Penguin
* Justice League: The Flashpoint Paradox (2013) - Voice of The Joker
* Batman: Assault on Arkham (2014) - Voice of The Joker
It's important to note that these are just some of his credits. Richard Trask has a long and varied career in voice acting, with many other projects to his name.