A truly "alien" character should feel fundamentally different in how they think and interact.
: Look at extreme life on Earth—such as microorganisms in extreme heat or cold—and scale them up to envision how life might adapt to a specific planet's landscape or gravity. such as unique eyes
: Effective descriptions often focus on shape and prominent features first, such as unique eyes, specialized limbs for locomotion, or bioluminescent skin. specialized limbs for locomotion