Solid Fog

When this spell is cast, the wizard creates a billowing mass of misty vapors similar to a wall of fog spell. The caster can create less vapor if desired, as long as a rectangular or cubic mass at least 10 feet on a side is formed. The fog obscures all sight, normal and infravision, beyond 2 feet. However, unlike normal fog, only a very strong wind can move these vapors, and any creature attempting to move through the solid fog progresses at a movement rate of 1 foot per round. A gust of wind spell cannot affect it. A fireball, flame strike, or wall of fire can burn it away in a single round. The material components for the spell are a pinch of dried, powdered peas combined with powdered animal hoof.