Dragon Ball Z: The World's Strongest

Dragon Ball Z: The World's Strongest is the second DBZ theatrical film, released in March 1990. Dr. Kochin uses the Dragon Balls to free his master Dr. Wheelo — a brilliant scientist whose brain was preserved in a mechanical body — from a glacier where he had been trapped. Dr. Wheelo seeks to transfer his consciousness into the body of "the world's strongest man," initially believing that to be Master Roshi before shifting his sights to Goku. The film introduces the concept of Bio-Warriors — powerful mechanically enhanced fighters — and gives Piccolo and Gohan extended combat roles alongside Goku's central battle.

The World's Strongest is notable for being one of the few DBZ films to feature Master Roshi as a significant plot element, providing nostalgic connection to the original Dragon Ball series. Dr. Wheelo's tragic backstory — a man of great intellect reduced to a machine who can never again touch the world directly — gives the film a pathos unusual for the theatrical lineup. Non-canonical but competently constructed, it stands as one of the better early DBZ theatrical entries. The bio-mechanical villain design would influence later Dragon Ball imagery and reflects the franchise's early engagement with science fiction as a complement to martial arts fantasy.