Crazy Hand

Crazy Hand (クレイジーハンド, Kureijī Hando) is Master Hand's left hand counterpart introduced in Super Smash Bros. Melee. While Master Hand's movements are very mature and easy going, Crazy Hand moves in dysfunctional and erratic ways. To fight him in Super Smash Flash, you have to clear Adventure Mode in any difficulty and deplete Master Hand's HP to the half, then procide to defeat both bosses. Crazy Hand looks exactly the same as Master Hand (apart from being a left-hand), but he acts more erratic and chaotic in general. He is impulsive, destructive, and consumed with a hollow feeling which comes from destroying one’s own creations.

Super Smash Flash
In Super Smash Flash, Crazy Hands appears exclusively for the Adventure Mode as the final boss alongside Master Hand. To fight him, you have to clear this mode in any difficulty, no matter if it's set on Very Easy to Very Hard, and deplete Master Hand's HP to the half and then, Crazy Hand will appear to aid Master Hand.

Unlike the orignal Smash games, both Hands doesn't make mix attacks, just like claps or double punch, and attack exactly the same, only that Crazy Hand is a bit faster than Master Hand.

Like Master Hand, Crazy Hand can't be defeated by normal means; instead, he has Heart Points (HP) which is altered based on the difficulty (for example, he only has 150 HP when fought on Very Easy mode) and must be depleted. Once 0 HP is reached for both bosses, they explode into the background and the mode is beaten.

Super Smash Flash 2
It is most likely Crazy Hand will return in Super Smash Flash 2 as the final boss of the Classic Mode only once more alongside Master Hand, only that he could appear only on hard settings, but since the game is still under development this is still uncomfirmed.

Other appearances
Crazy Hand appears in the Game Boy Advance game Kirby & the Amazing Mirror alongside Master Hand, as the bosses of Candy Constellation.

However, the concept of the Hands may have come from a boss called Wham Bam Rock from Kirby Super Star and Kirby Super Star Ultra (the game's remake), who attacked Kirby with a stone hand that used different slaps, pokes, and grabs. In the updated version, Kirby Super Star Ultra, a crystalline version called Wham Bam Jewel appears, with more parallels to the two hands.