Nim Nim is a drug dealer who arrived at the facility in search of new fungus to use as magic mushrooms to increase business. She secretly believes that she is descended from the creatures within the Verdant Cradle, as she never knew her family. Nim Nim sees Eleanor Halliday as a visionary, and has previously hallucinated talking to her while high on drugs.
Nim Nim serves a shadowy figure known only as The Boss, who took her in as a child and named her Nim Nim. She unquestioningly obeys anything they ask.
Nim Nim first received communications from her Boss while in the facility when they informed her about Project White Iris and told her to collect the White Iris for them, but warned her to be careful that it didn't touch The Mycelium Vitae, for if it did Nim Nim would die.
They next heard from them as the Boss messaged her to tell her of the Stinkrot plant, which could be used to create a powerful hallucinogen. Nim Nim later encountered an illusion of the Boss conjured by the Stinkrot's gas, which attempted to convince her into merging with the Mycelium hivemind.
Nim Nim finally met her boss in person for the first time when the group encountered Gaia, a five-headed Mycelium monster underneath the facility. In the end, her love for her new found family in her party members won out over her loyalty to her boss, and she used the white iris to kill Gaia.