Zar

First there was UNO. Well, first there was Crazy Eights, but never mind.

Then came Zar which added even more viciousness. The "draw two" card in Zar is a colored Wasp. The trick is, if you play a Wasp in response to being zapped by a wasp, then the opponent to your left must draw 2 cards equal to the numbers of wasp cards in the stack, unless your opponent plays a wasp which would make the next player draw even more cards unless HE also played a wasp, etc.

It's not uncommon for players to quickly draw huge handfuls of cards. There is a nice balancing mechanism however. If you can match an identical card that someone just played you can "match" the player by quickly discarding the card. The player who played the original card must draw one card and play passes to the next player from the person who laid the Match. So the more cards you have in your hand, the more matches you can make to get rid of them.

Zar has a faster pace than UNO and constantly keeps you on toes to match your opponent's cards. This increases player interaction, excitement, and much more chaos.

If even Zar becomes too tame for you check out The Totally Insane Card Game.