In William Shakespeare’s Richard III, the title character is a hunchback whose anger is fueled because he feels like an outcast. His quest for power becomes a form of revenge. Under Robert O’Hara’s direction, Richard III for the Public Theater is loose and playful. Actress Danai Gurira, in the gender-swapped title role, is sinewy and tiger-like. As Richard, she pounces, manipulates, smiles, grins, and grimaces: a shape-shifter who manipulates others.