Berni developed certain polimaterial objects known as “Los Monstruos” (The Monsters), in which the picked up elements abandon the plane to set up in space. These large assemblings, made of most diverse materials (wood bobbins, balusters, rubber seals, street lamp remainders, steering wheels, watercloset lids, egg packagings, old radios, baskets, fizzy drink caps, popular masks, adornments in tin, bicycle parts, washing machine blades, etc.) had been preceded by a set of relieves he had begun in Paris, in1962, devoted to lubric versions of Ramona and other beastly characters, performed on a reduced scale.
The consonance of Berni’s polimaterial work with the local version of pop art lead artists as Delia Cancela, Edgardo Giménez, Pablo Mesejean, Dalila Puzzovio, Carlos Squirru and Zulema Ciordia to consider him a precursor. Because of this he took part with them in the exhibition La muerte, performed at Galería Lirolay, Buenos Aires.