Loo resides as one of three human children on the planet Cronkee within the Unicorn system, living alongside siblings Sap and Pom under their mother's guardianship. Their mother founded this home after driving off Kig-Yar pirates. When SPARTAN-1337 crash-landed on Cronkee, Loo and the siblings initially believed the armored figure to be a robot. After witnessing SPARTAN-1337 battle the genetically enhanced Jiralhanae Pluton, Loo and the siblings urgently sought their mother’s aid. Loo personally rallied local siblings Guy and May—both skilled combatants—to reinforce SPARTAN-1337 against Pluton. Following Pluton’s defeat, Loo safely returned home with the group and recounted the entire encounter to their mother.