Steve Viksten ( July 19 , 1960 -- June 23 , 2014 ) was an American television writer and voice actor who was best known for voicing the character Oskar Kokoshka on the Nickelodeon animated series `` Hey Arnold ! ''
Steve Viksten ( July 19 , 1960 -- June 23 , 2014 ) was an American television producer , writer and voice actor . He was best known for voicing the character Oskar Kokoshka ( and co-creating , writing and producing ) on the Nickelodeon animated series `` Hey Arnold ! ''