Bombchu

A Bombchu is an item originating from the Legend of Zelda series. It appears as an item in Super Smash Bros. for Nintendo 3DS / Wii U and Super Smash Bros. Ultimate. Once a player activates a Bombchu by throwing it, it continues moving in one direction in a non-stop path, going over obstacles, walls and even ceilings or under the stage. Once a player touches the traveling Bombchu, it explodes on impact, damaging the player. Bombchus can be destroyed by lava and other attacks, however.

Super Smash Bros. for Nintendo 3DS / Wii U trophy information
Blue indicates exclusive to the Wii U version.