Joker card

Throwing Cards

In the Animated Series, The Joker had metal cards, he can throw them like a ninja's shuriken with amazing accuracy. They're often seen as Joker's analouge to Batman's batarangs. They have appeared in a few video games since then, never a comic book.

Poison Cards

The Joker once poisoned a regular paper deck, with sharpened edges giving a deadly paper cut.