Phoebe Heyerdahl is Helga Pataki's best friend in the Hey Arnold! franchise. She is a young half-Japanese girl who was born in Kentucky before moving to Hillwood. She is one of the smartest fourth-grade students in P.S. 118, to the point that she was once given a pass to the sixth grade. She is often there to give Helga someone to confide in, and she is also one of the few characters to know about Helga's crush on Arnold. Phoebe also has a crush on Gerald Johanssen, which appears to be mutual.