Young Justice Recruits Brent Spiner and Alyssa Milano for the Injustice League

Here comes the Injustice League! In tonight's episode of Cartoon Network's Young Justice, a secret society of super villains emerges — and there's some cool voice casting on the roster. Star Trek: The Next Generation's Brent Spiner (who appeared on last night's Big Bang Theory) stars as the Joker, while Charmed vet Alyssa Milano plays Poison Ivy.