Mad Monster Party?

Synopsis

Dr. Frankenstein discovers the secret of total destruction and decides to retire. He invites all the renowned monsters of the world to his Caribbean island where he will elect an heir who will inherit his awesome secret. Dracula, Dr. Jekyll, The Invisible Man and many others are there ... including his nephew Felix who seems to be totally ignorant of what is happening. Felix falls in love with Dr. Frankenstein's ward, Francesca who, unknown to Felix, is one of Frankenstein's "machines". He is in for a surprise - and so is Francesca, who doesn't know what Felix will turn out to be, as the sun sinks slowly in the west.