Several sequences were filmed but cut from the final release, including: a sequence where Brundle sends a cat and the surviving baboon through the telepods,
resulting in a mutated creature he beats to death with a pipe; a scene where Brundle climbs the outside of his building as an insect limb emerges from his side;
and an alternate ending in which Veronica has another dream of her unborn child, this time as a baby with beautiful butterfly wings.
The inspiration for the design of the telepods came from the shape of the cylinder in director David Cronenberg's vintage Ducati motorcycle. Brundlefly's "vomit drop" was, in reality, made from honey, eggs, and milk.
It took nearly five hours to apply the most extensive makeup stages to actor Jeff Goldblum.
The Chris Walas, Inc. designers studied graphic books on disease as a starting point for their "Brundlefly" makeup/creature designs.
The final "Brundlefly" creature is horribly deformed and asymmetrical. This reflects director David Cronenberg's idea that the creature shouldn't be a giant fly, but rather a literal fusion of a man and an insect that embodies elements of both.
The famous tagline, "Be afraid. Be very afraid", originated in this film as dialogue spoken by Veronica Quaife (Geena Davis).
