The Poison Capsule is a small, spherical item with a slightly translucent greenish hue, resembling a glass vial filled with toxic liquid. Its surface is smooth with a subtle pixel-art texture to match Factorio's isometric style. The capsule features a metallic cap with fine grooves for grip, and the liquid inside appears to glow faintly, indicating its poisonous nature. The design is simple yet effective, with clear visual cues for its function.