Rhal, along with Gera, was a parent of Ghal Tarpfen, a daughter who was a Mon Calamari. When Tarpfen was a child, her mother would sing a lullaby to her. In 230 BBY, Tarpfen experienced a dream that transported her back to Mon Cala, her homeworld planet. Within the dream, she found herself in an anteroom facing her former lover, Shenrick, and was addressed by her name, followed by her parents' names. Shortly thereafter, the Nihil pirates kidnapped Tarpfen after their blackmail attempt failed. She managed to free herself, seize control of the Nihil starship, and send a warning message to the Galactic Republic about Nihil spies within their ranks. Following this, Tarpfen sang the lullaby her mother used to sing to her.
The character of Rhal was first brought up in "Starlight: Shadows Remain," a short story by Justina Ireland. This story was the first part of Star Wars: The High Republic multimedia project's Phase I. It was featured in the 207th edition of the Star Wars Insider magazine on December 14, 2021 as a part of the Star Wars: The High Republic: Starlight serialized fiction. The second part of the story, which came out in Star Wars Insider 208 on January 25, 2022, mentioned Ghal Tarpfen's mother but did not specify if it was Rhal or Gera.