In the Smash series, the term "unplayable character" refers to a character featured in the game that cannot be obtained for use by in-game means. These characters can be controlled via the use of a GameShark or Action Replay, but since these characters are not meant to be playable, they can cause glitches or freeze the game.
Fighting Polygon Team
The Fighting Polygon Team is faced on stage 10 of the 1P Game, as well as in the Race to the Finish bonus game. The team is made up of polygonal models of the 12 playable characters, but are weak and lack Special Moves.
Due to the Super Mushroom and Metal Box, Giant DK and Metal Mario are no longer unplayable. As well, the randomized nature of Classic Mode can give the "giant", "metal" and "team" modifiers to playable characters.
Fighting Wire Frames
The spiritual successors to the Polygon Team, the Fighting Wire Frames come in male and female varieties. They appear in Adventure Mode, as well as the various forms of Multi-Man Melee.
Master Hand once again reappears as the boss of Classic Mode, sporting a revamped moveset but still relying on stamina. He also appears in Event Match 50. It is possible to play as him with the Master Hand glitch, but this was not intended, making him an unplayable character.
Crazy Hand is a left-handed glove that pairs up with Master Hand to double-team players. He can be fought in Classic Mode if certain conditions are met, as well as in Event Match 50.
A huge, mutated version of Bowser, Giga Bowser is a hidden boss that appears in Adventure Mode if you beat the mode without using a continue on normal or higher in under 18 minutes. He also appears in Event Match 51.
Giant Kirby is a gigantic version of Kirby. appears in the Green Greens stage only after beating the Kirby team in under 30 seconds..
Metal Luigi is a metallic version Luigi. He appears in stage 11 of Adventure Mode fighting alongside Metal Mario only when Luigi is unlocked and appears as a random opponent with other metal characters in stage 10 of Classic Mode.
The Subspace Army is featured as the major antagonists of the Subspace Emissary mode. See the main article for more information on the soldiers of the army.
Sandbag once again returns in the Home-Run Contest as the object of beating up. He also appears in the lobby of the Wi-Fi Multiplayer mode to "practice" on while the game is loading. It is also an item in Super Smash Bros. Brawl and drops other items when it is attacked.
Master Hand reappears once again in Classic Mode as the final boss. He also appears in the Subspace Emissary cut scenes, however is never battled in the gameplay.
Crazy Hand reappears once again in Classic Mode as the final boss fighting alongside Master Hand only when the player reaches the final stage in 9 minutes or less with the difficulty set to Hard or above without using a continue.
Petey Piranha appears as the first boss of the Subspace Emissary mode. He has Peach and Zelda trapped within cages, and breaking the cages via damaging them is apparently the only method to defeat him.
Ridley is another boss in the Subspace Emissary, fighting Pikachu and Samus.
Meta Ridley is a mechanized version of Ridley that attacks the Falcon Flyer and is fought by R.O.B., Diddy Kong, Captain Falcon, Pikachu, Donkey Kong, Olimar and Samus.
Rayquaza is another boss in the Emissary, being fought by Fox and Diddy Kong.
Galleom is a large robot that transforms into a tank, being fought by Marth, Ike, and Meta Knight in the first fight and by Lucas, and the Pokémon Trainer in the second fight.
Duon is a boss made from the Mr. Game & Watch clones being fought by Fox, Sheik, Peach, Lucario, Snake and Falco.
Fighting Alloy Team
The successor to the Fighting Wire Frame and Polygon teams, the Fighting Alloy Team comes in Red, Blue, Yellow, and Green varieties.
Tabuu is the final boss of The Subspace Emissary and the leader of the Subspace Army.