Justice League

Ben voiced the DC comic book character Bartholomew Aloysius Lash, known to friends as Bat Lash, in an episode of Justice League Unlimited in 2005.

The episode is season1, episode12, The Once and Future Thing: Weird Western Tales, Part 1. You can read a full synopsis of the episode at the DC Animated Universe Wiki and a bio of Bat Lash at DCAU Resources.

Amazon has the episode available for download for $1.99.

Images from DC Animated Universe Wiki and DCAU Resource