Arnold is a peach color. His hat is light blue. His shirt is blue-green with a red collar. He has yellow hair. Arnold's pants are blue and red. He has black shoes. Arnold's eyes are white with black pupils.
In the Claymation shorts, Arnold's shirt is blue. His skin color is the same. Arnold's hair is a lighter shade of yellow. Mostly everything is the same as in the television series.
Arnold has appeared in every episode of Hey Arnold!. His first apperance was in the short "Arnold Escapes From Church". His last appearance was in the episode "Phoebe's Problem".