Prometheus: Fifield Mutation Concept Art by Ivan Manzella
In the original script of Prometheus, when Fifield became infected with the Black Gloop it mutated him into a very familiar Xenomorph looking being, rather than the mutant monster which actually appears on screen. I believe the full Xeno transformation was deemed a little too obvious in the end so they went with the mutant look instead. Here’s the original concept art for the cut transformation so we can now see what could have been.
they shoulda gone for it, the third photo is the perfect mix of xeno and human. It woulda been better then the zombie...