This move involves Captain Olimar quickly pulling a Pikmin out of the ground. What Pikmin is pulled out is random in Brawl; what type of terrain where this move is used has some influence on what type of Pikmin will be pulled out more often. In Smash 4, however, there is a set order in which color Pikmin is pulled out: red, yellow, blue, white, purple, and back to red. Olimar can have up to six Pikmin following him in Brawl and three in Smash 4; trying to pluck another, or using the move in the air, will result in Olimar grabbing nothing and being vulnerable for a moment.
Upon being plucked, Pikmin arc backwards over Olimar's shoulder and land behind him. As a result, doing the move too close to an edge will result in the Pikmin falling off, possibly to their doom if there is no ground below. These Pikmin can be saved with a Pikmin Order after they have fallen below where Olimar is standing. White and Purple Pikmin have a smaller arc than Red, Yellow, and Blue ones, so it is possible to let the three common colors be sent over the edge while keeping the rare ones with correct positioning (and standing even closer to the edge will only allow Whites to land, until the point where all types will fall).
Kirby is unable to copy this move exactly. Instead, Kirby combines Pikmin Pluck with Pikmin Throw. The Pikmin that Kirby creates are chucked forwards, collide with opponents, do damage based on color (Red 1%, Yellow 2%, Blue 3%, Purple 4%, White 5%), and die immediately after landing. Kirby's Pikmin follow the same probability rules as Olimar's. 
Special Move customization was added in Super Smash Bros. 4. These are the variations:
In the Pikmin games, Pikmin born from Onions fall into the ground as seeds, where they can be plucked by a leader. Leaving a Pikmin in the ground before plucking it will allow it to develop from a leaf to a bud and finally a flower. To make more Pikmin seeds, Pellets or dead creatures must be carried to and absorbed by the Onion. Up to 100 Pikmin can be outside the Onion at once; there is no theoretical limit to how many can be inside.