Grand Finale! Invention Explosion! is eighteenth and final volume of the Dr. Slump manga series written by Akira Toriyama. It was released on May 10, 1985 in Japan and in May 5, 2009 for the English version. Set in 1985, this volume most notably deals with Taro Soramame joing the police force, the introduction of Charmy Yamada and the 2nd Annual Penguin Village Grand Prix.