"Harvey" by Mary Chase

INDOOR THEATRE
Elwood P. Dowd insists on
including his friend Harvey in all of his sister Veta’s social
gatherings. Trouble is, Harvey is an imaginary six-and-a-half-
foot-tall rabbit. To avoid future embarrassment for her
family—and especially for her daughter, Myrtle Mae—Veta
decides to have Elwood committed to a sanitarium.
But it seems that Elwood and his invisible
companion have had a strange influence on more than one
of the doctors. Only at the end does Veta realize that maybe
Harvey isn’t so bad after all.