In Season 3, the Mind Flayer’s massive spider-like form is a physical manifestation, but not its ultimate or “true” form, which is a shapeshifting, particle-based entity from the Abyss. Physical vs True Form The Mind Flayer is an ancient, malevolent entity originating from the Abyss, capable of existing in multiple physical forms through possession and control of living creatures or objects via silver-black particles. In Season 3, it appears as a massive, spider-like creature, which is the form it takes to interact with the physical world and exert influence over Hawkins. This form is designed to be visually imposing and to serve as a tangible threat to the protagonists, but it is not the Mind Flayer’s ultimate essence.