Damage Kirby's Vacuum attack does when Kirby spits his foe out with the "A" button - Depending on which character Kirby spits out, if the star hits a foe it can do anywhere between 9-19%(not 11% though). Usually the star does more % to any unlucky foe who gets hit by it if the character Kirby's spitting out is big and/or heavy (for some exceptions like with Fox and Falco, who are relatively small for their power). 

---Side note, characters on Giant Melee and/or with a Super Mushroom do more damage than normal-sized characters do, and characters on Tiny Melee and/or with a Poison Mushroom do less damage than normal-sized characters do.

19% - Bowser / DK
18% - Captain Falcon / Ganondorf / Link / Samus / Yoshi
17% - Dr. Mario / Luigi / Mario / Mewtwo
16% - Fox / Ice Climbers / Ness
15% - Falco / Marth / Peach / Roy / Sheik / Zelda
14% - Young Link
13% - Mr. Game & Watch / Pikachu
12% - Kirby
10% - Jigglypuff
9% - Pichu