Vine Whip is Ivysaur's Up Special Move. With this move, Ivysaur send a vine out of his flower in order to do a Tether Recovery. Ivysaur will also gain a small amount of upwards distance. There are two "forms" for Vine Whip. The first is when Ivysaur is on the ground, Vine Whip being an attack that attacks at a forty-five degree angle in front of and above Ivysaur, with a powerful sweetspot at the end of the whip. The second is when Ivysaur uses it as a recovery, in which Vine Whip gains a deceptively long range, capable of nabbing the edge with a length far beyond the ground-based Vine Whip. Unfortunately, Ivysaur can easily be edgehogged while attempting to use the Vine Whip to recover. This can, however, be prevented by shooting a Razor Leaf to clear the edge-hog off the stage.
Ivysaur's grab also involves using it's vines as arms.
Origins
In the Pokémon games, Vine Whip is a fairly standard grass type move. It is very frequently seen being used by Ivysaur and its evolutions, and other Grass Pokemon in the anime, but is considered one of the weaker grass type moves in-game. These vines act as long arms to those with no hands.
Trivia
If used from far enough away, grabbing the front end of the Pirate Ship will cause Ivysaur to swing into the boat, rocketing downwards and resulting in a self-destruct.