Arnold's best friend Gerald is this to him. Arnold is much more serious than he is, while Gerald is more immature. Arnold is also very optimistic, while Gerald is more cynical. Furthermore, Arnold dresses in blue and is a blonde while Gerald dresses in red and is a brunette.
Phoebe to Helga, being rather calm while she's rather aggressive. In addition, Phoebe is the shortest student in her class while Helga is fairly tall. Also, she dresses in blue while Helga dresses in pink.
Lila is a foil to Helga in almost every way. Lila is a poor country girl, Helga is a middle class city girl. Lila is pretty, Helga could be generously described as Ugly Cute. Lila is liked by everyone while Helga is disliked by everyone. Helga has a crush on Arnold, but acts as a Loving Bully to him, while Arnold has a crush on Lila, but she shoots him down gently. And according to Word of God, Lila has a repressed dark side. So in addition, while Lila is sweet and innocent on the outside, but emotionally disturbed on the inside, Helga is mean and crazy on the outside, but kind and sophisticated on the inside. Lila represses her negative qualities and Helga represses her positive qualities for the exact same reason: they feel that showing them would be detrimental, when in fact doing so would be healthier for the both of them.
Helga is also this to Arnold. Both are the blonde-haired stars of the show with an Improbable Hairstyle and Iconic Item that adorns their head (Arnold's little blue baseball cap, Helga's giant pink bow), and are probably the smartest among their peers. Arnold is a sweet and friendly person who rarely gets angry and who grew up in an "atypical" family but was given love, respect, and attention. Helga is a mean and anti-social girl who does have a kind side she keeps hidden and grew up in a "typical" family but was emotionally neglected by her parents in favor of her successful older sister. Then there's their love lives: Arnold has many crushes over the course of the series and they never work out, while Helga only has eyes for Arnold and they become a couple at the end of The Jungle Movie.
Doug LeSham is almost like Oskar in being a con-artist except for a few differences: Deep down, Oskar is a good person who really loves his wife, would never commit infidelity and can feel great remorse if he's done something to deeply upset her or anyone else and is willing to fix those things. Meanwhile, Doug is willing to commit infidelity and/or bigamy and has no guilt in lying or hurting people.
Both Doug LeSham and Arnold are blond love interests to a daughter of the Pataki family. However, Doug is a philandering conman, while Arnold is kind and honest.
