UNO: Polly Pocket

From BoardGameGeek:

The usual UNO rules - Players race to empty their hands and catch opposing players with cards left in theirs, which score points. In turns, players attempt to play a card by matching its color or number to the topmost card on the discard pile. If unable to play, players draw cards from the draw pile until they are able to place a card. Wild and special cards spice things up a bit. Additionally, when playing their penultimate card from their hand, players must shout 'UNO' or face a forfeit of drawing two further cards. WHAT MAKES THIS DIFFERENT FROM TRADITIONAL UNO: Rockin' Blockin' card - a special wild card that can be used in two different ways: Rock the card: Play this card and each of your opponents must draw one card from the draw pile. Block their cards: If the player before you plays a Wild Draw 4 card, you can instantly discard the Rockin' Blockin' card to block their card. If you do this, you don't have to draw four cards and you still get to take your turn.