Knu, originating from the non-aligned nation of Vidnu, possesses a distinctly non-human physiology. He appears as a tall, scaly humanoid with reptilian features, a unique presence among the crew. His species' precise biological classification remains undefined.

Throughout events, Knu exhibits an exceptionally calm and analytical nature, consistently acting as the primary voice of reason during crises. He deploys extensive knowledge across multiple disciplines, successfully identifying the hazardous "conductor vines" overtaking the engine room and deducing their link to the rising temperatures. His sharp observational skills and logical methodology establish him as a stabilizing force within the group.

Knu maintains a reserved personality, rarely showing overt reactions even under severe stress or suspicion. He methodically evaluates situations and individuals, applying his intellect to navigate challenges such as the ship's decaying orbit and the enigma of the eleventh member. His initial suspicion targets the protagonist, Tada, grounded in rational analysis rather than emotional bias.

A pivotal moment occurs when Knu directly confronts Frol about his biological characteristics after an accidental observation during a shower incident. This encounter leads Knu to reveal Frol's unique physiology and cultural background to the group. His clinical handling of this sensitive information underscores his role as an expositor of truth within the tense environment.

Following the ship's events, Knu returns to his home planet and pursues a career as a poet, a professional choice reflecting his contemplative nature.