Barrel Cannon.

The Barrel Cannon is an environmental feature in Super Smash Bros. and Super Smash Bros. Melee and an item in Melee. The item can be picked up and thrown. The first character (other than the original thrower) that touches the cannon will be trapped inside until they press A or are KO'd when it falls or shoots them offstage. Touching any Barrel Cannon will cause a character to be stuck inside while the barrel spins around. If A is pressed when inside, the cannon will shoot the occupant in the direction the arrow on the barrel is pointing. If nothing is pressed, the barrel will automatically fire the occupant in the direction it is pointing. It turns the character into a projectile while moving, damaging foes that are hit. Also, a tech is needed to recover as landing will stun the character.

These are permanently placed on the bottom of Congo (Kongo) Jungle (N64) and Kongo Jungle (GCN) for recovery. They move back and forth and spin around. In the Melee stage, a Klaptrap will occasionally get stuck inside. While it is inside, the cannon cannot be used by anyone; those who touch it will be damaged by the Klaptrap. Eventually the Klaptrap will be shot out, occasionally straight up through the stage. This will cause high damage, knockback, and even KO those with high damage.

If a character is in it and another character runs into it, it causes damage (around 16, but multiple times).