Lethal Hamster is a diminutive hamster wielding disproportionately oversized weapons like kitchen knives or baseball bats. He materializes abruptly in workplace settings, brandishing these implements to threaten coworkers, though no on-screen fatalities occur. Narrative implications hint he may have murdered a toucan offscreen.

During office meetings or at the boardroom table, colleagues seldom acknowledge him directly. His unexplained access to rooftop-stored sunflower seeds—despite lacking flight—fuels persistent theories among other characters that he might be an imaginary construct.

Throughout all media adaptations, his role remains static with no evolution in behavior, relationships, or background. Concrete details about his origins or development are absent, and his reality status persists as an unresolved mystery.