Sailor Helga is a Hey Arnold! Sailor Moon crossover fanfiction created by Shameonpretzel.
In the fanfic, Helga meets Luna the cat and takes on the role of guardian of love and justice as she fights to protect her family and friends in the city of Hillwood. Along the way, she gains new members to her team: Phoebe Heyerdahl becomes Sailor Mercury (Sailor Phoebe), Rhonda Wellington Lloyd becomes Sailor Mars (Sailor Rhonda), Big Patty Smith becomes Sailor Jupiter (Sailor Patty), and Lila Sawyer becomes Sailor Venus (Sailor Lila). The team also encounters a mysterious masked stranger who looks a lot like Arnold Shortman.
Sailor Helga was inspired by the username of the webmaster of the Hey Arnold fan page Gerald's Gateway of Tales.