Barbell

Barbells are objects that first appear in Donkey Kong for the Game Boy, then subsequently appear in a handful of games in the Mario vs. Donkey Kong series.

Donkey Kong (Game Boy)
Barbells appear in Stage 9-9 of Donkey Kong for the Game Boy during the final battle against Donkey Kong. When Donkey Kong slams the ground, barbells and barrels drop from above. If Mario is hit by a barbell, he loses a life.

Mario vs. Donkey Kong
Barbells reappear in Mario vs. Donkey Kong, specifically in Donkey Kong Plus. They fall down once Donkey Kong slams one of his mech's arms on the ground.

Mario vs. Donkey Kong 2: March of the Minis
Barbells appear in Room 1-DK in Mario vs. Donkey Kong 2: March of the Minis, dropping along with barrels when Donkey Kong slams the ground. They behave identically to their previous appearance. If a Mini Mario comes into contact with a barbell, the Mini Mario breaks and the barbell disappears.