10 Things You Probably Didn't Know About The Cloverfield Franchise

As with most films that include CGI monsters, it becomes difficult for the actors to react to something that is never there. In the second act of Cloverfield, the characters find themselves within the underground of New York, finding refuge in the subway. After listening to the chaos above them that they have just escaped, they discover the secondary creatures that eventually go on to kill Marlena as her chest explodes in the army base - the parasites.

Audiences will remember the speedy and creepy nature of the parasites as they chase the group through the subway tracks, extensions of the clover creature when they are shed earlier in the film.

Originally, however, the parasites were puppets, designed to be fully formed for the actors on set to react with. Production designers soon discovered that they were too 'muppety' and opted for the CG version instead for the final cut.

Reeves has since confirmed that this was a useful tool for the actors to know what they would be up against when the puppets were taken away as they looked much like the finished cinematic version.