Erro was born in 1932 in Iceland. Studied at the Academy in Reykjavik and in Oslo. From 1955-1958 studied at the Academy in Florence and learned the art of mosaic. He made several mosaic floors in Reykjavik. In 1957 he travelled to Israel and in 1958 he moved to Paris. In 1962 he staged the Happening, Catastrophe with J. J. Lebel, made his first film in Venice. In 1964 he began his film Grimaces and travelled to Russia. He was also represented at the Tokyo Biennale at the exhibition Le Surrealisme. He visited New York and in 1966 made the film Stars. In 1967 he showed at the Musee d'Art Moderne de la Ville de Paris and in Science Fiction in Berne.

His paintings combine elements of the comic and science fiction with stylistic techniques influenced by Surrealism. He travelled to Cuba and in 1968 to the Soviet Union and to the USA. He had exhibitions in Paris and Cologne in 1969 at the ARC, Paris. In 1971 he spent a year in Berlin and a year later made a long visit to Thailand and the Far East.