Fierce Creatures Easter Egg - Willa, Not Wanda

Towards the end of the film, when Rollo (John Cleese) and Willa (Jamie Lee Curtis) are exchanging dialogue, Rollo accidentally calls Willa, Wanda, a concealed reference to A Fish Called Wanda, the previous film to feature all of the cast members.

It was put in there by the scriptwriter (who, incidentally, was Cleese himself) because at the time of the making of the film, everyone thought wrongly that it was a sequel to A Fish Called Wanda. So Cleese himself stated that it had "no Wanda references whatsoever". So he added a small, insignificant, yet not unnoticeable reference, to have his own laugh at everyone.