Osvaldo Walter Viola was a comics author and teacher from Buenos Aires, who worked under the pen name Oswal. A self-taugh artist, he started his professional career in 1957 in the pages of magazine Ella. He subsequently made illustrations for books and magazines by Editorial Haynes, including such publications as El Hogar, Selecta and Mundo Infantil. He made cartoons for El Correo de la Tarde before doing his first comic book work for Editorial Frontera.
He drew several stories in Oesterheld's 'Ernie Pike' series for Hora Cero. He had his real breakthrough as a comics artist with his comics adaptations of 'David Copperfield' and 'Robinson Crusoë' for magazine Anteojito in 1965. A year later, he created one of his best-known characters, Argentina's first superhero 'Sónoman', whose adventures he wrote and drew for ten years, drawing inspiration from DC Comics. A Sónoman magazine was published by Ediciones de la Urraca in 1975, made entirely by Oswal. The publication disappeared after only two issues due to an economic crisis.
Oswal's other famous creation is 'El Espíritu de Mascarín', of which fifteen episodes were published bin Chaupinela magazine from 1975. Other creations include 'Detective en Hollywood' with Linton Howard for La Hoja (1979), 'Tito Mamut' and 'Camino a Esteco' with Carlos Albiac in Bang! (1981), 'El Bígamo' in Satiricón (1982) and 'Claudio Forroquina' with Dalmiro Sáenz in Superhumor (1982).
From 1974 Oswal was present in Skorpio, with stories in cooperation with writer Ray Collins, Carlos Albiac and Héctor Germán Oesterheld. During the 1970s and 1980s he contributed to several Argentine magazines, such as Siete Días, Satiricón and Superhumor, but also to Cimoc from Spain. For this magazine, Oswal created such comics as 'Mark Kane', 'Big Rag' (with Albiac), 'Buenos Aires (with Ricardo Barreiro), Las Putas y el Loco' and 'Consummaatum est'.
Much of his work from the 1980s was published in Spain, Italy and France, while 'Buenos Aires' was also published in Dutch. New work included the series 'Pieter Thijsz', '13 Relatos Negros' and 'Sombres Destins', the latter with Enrique Abulí for Albin Michel in 1998. Oswal continued to work for Anteojito during the 1990s, but also for the children's supplement of the newspaper La Nación. These papers ran the adventures of 'Lejos Pratt', another cooperation with Albiac. His book 'Tango en Florencia' was published in Argentina in 2006.