The Incredible Mr. Limpet (VHS 1990) 

Live-action and 2D animation combine to tell the story of a man who longs to be a fish after he is classified by the Navy as an F4 - too small and weak to be a soldier. When his dream of being a fish becomes a reality, Henry uses his underwater prowess to become the Navy's strongest secret weapon.

Don Knotts, Carole Cook, Andrew Duggan, Jack Weston

Based on the novel by Theodore Pratt  

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