I think these are complete apart from the figure coming out of the cake is missing their hair piece. Please look at pics to be sure. Also comes with leaflet/flyer and two used/opened bags. 

From Lego website:

Bring exciting new play possibilities to existing LEGO® sets with the celebratory LEGO® Minifigures 71021 Party series. This festive series of fun collectibles comes with an array of new-for-April-2018 costumes and accessories, including a balloon on a string, a cute little mouse and a surprise party cake, and features a host of brightly dressed characters, all ready to party. The Party series lineup includes the Dragon Suit Guy, Firework Guy, Elephant Costume Girl, LEGO Brick Suit Guy, LEGO Brick Suit Girl, Cactus Girl, Party Clown, Cake Guy, Unicorn Guy, Flowerpot Girl, Birthday Party Girl, Birthday Party Boy, Spider Suit Boy, Cowboy Costume Guy, Race Car Guy, Cat Costume Girl and, last but not least, a replica of one of the first minifigures ever produced—the 1978 Police Officer. Each minifigure comes in a sealed ‘mystery' bag, together with one or more accessory elements, plus a collector's leaflet and a unique display baseplate.