Shotzos are common enemies in the Kirby series. Similar to Gordos, these cannon-shaped enemies cannot be defeated by using any attacks, including Kirby's invincibility, unless they're dropped into the pit by breaking the blocks that they're placed upon. As they are cannons, they cannot move around, but they can aim in up to 5 directions. They shoot a fast, spiraling cannonball at Kirby, which later disappears at a certain distance.
Shotzos appear in Super Smash Bros. for Nintendo 3DS as common enemies in Smash Run. Like Gordos, Shotzos are immune to attacks and as a result, cannot be defeated. In addition, if a player returns to an area with a Gordo or Shotzo, they will reappear again when the player nears that spawn zone, rather than completely disappearing like all other enemies. Shotzos fire in either a three round burst in one direction or one round aimed at the player's position when it fired.
In Super Smash Bros. for 3DS
These cannons from the Kirby series could track Kirby and fire at him. In Smash Bros., there are two different kinds: ones that fire in a set direction and ones that will track and fire at a fighter. Don't waste time attacking these guys, though--it's impossible to defeat them.