Ryan Coogler was finishing Marvel's historic Black Panther superhero movie when a panther figure of a different kind came into his life. He and his wife, Zinzi, were having dinner in the Brooklyn backyard of filmmaker and friend Shaka King (having first met in 2013 at Sundance when premiering their first features, the police brutality drama Fruitvale Station and the hip stoner comedy Newlyweeds, respectively)...