From the Super Mario Wiki
The Subspace Army is an evil organization made up of formless beings in the Subspace Emissary of Super Smash Bros. Brawl. They are the main antagonists, led by the mysterious character, the Ancient Minister. It is later revealed that the Ancient Minister was forced to lead the army by Ganondorf, Bowser and Wario. The trio were the ones truly controlling the army and did so under the orders of Master Hand. Master Hand is later revealed to be controlled by Tabuu, the true leader of the army. The Subspace Army's main troops are a group of small shadow beings, known as Primids. Their goal was to pull the entire world into Subspace so as to destroy it. They hoped to accomplish this by using a powerful and deadly weapon known as the Subspace Bomb. The army is also in command of a large assortment of weapons and doomsday devices such as the Subspace Gunship, a flying fortress that could trap entire areas in subspace without the use of the Subspace Bomb. Petey Piranha, Porky, Ridley, his Meta form, and Bowser's Koopa Troop are also members of the Subspace Army. The creatures in the Subspace Army were created from Shadow Bugs, which originated from Mr. Game & Watch. The army also has in their possession a weapon known as the Dark Cannon, used by both Bowser and Wario to turn other characters into trophies.
The Subspace Army