Early drafts for the Aliens vs. Predator sequel did have the Predalien, but not for very long. A crash landing killed the creature in the draft’s opening pages. When Greg and Colin Strause were brought on to direct the project, the first thing they did was demand a rewrite that kept the Predalien alive. According to them, this was the main villain of the film. They weren’t going to allow it to be destroyed in the first few minutes. This was good news to Alec Gillis and Tom Woodruff, owners of Amalgamated Dynamics Inc, the special effects company that houses the elements for the Alien and Predator costumes. The pair were eager to work on the Predalien, but once it was confirmed, the pair had to get down to the work of designing it.
Despite several pre-existing looks for the Predalien, provided by the comic books and video games, Gillis and Woodruff decided to start from scratch. Several different iterations were considered. Some had more elements of the Predator. Others looked much more like the Alien. Eventually, it was decided that instead of making the Predalien look like it was half Alien and half Predator, it would instead look like an Alien with a few Predator traits. Gillis and Woodruff focused on the two most recognizable Predator features: The mandibles and dreadlocks. They put these on an Alien who was more bipedal than a standard warrior, a bit more muscular around the chest, and with an amended dome to look more like a Queen’s. They also placed a Predator skull inside the head, a throwback to the creature in the original Alien, which had a human skull.
The film also introduces a new, and much more controversial element to the creature: A different lifecycle. Until Requiem, the Xenomorphs had a rigidly defined method of reproduction. A Queen lays eggs, from which jump Facehuggers. Facehuggers plant an embryo inside their victims, from which spews a Chestburster, after a period of incubation. The Chestburster molts its skin and eventually becomes the full-sized adult that is familiar to audiences around the world. A deleted scene from Alien (reinserted into the Director’s Cut, although its status as canon is still up for debate) shows a solitary Xenomorph, deprived of the hive structure, gestating new eggs from the organic material in humans. However, even that pales in comparison to the new method used by the Predalien. In this case, the Predalien directly deposits up to five chestbursters in a single host, bypassing the need for eggs and Facehuggers entirely. This choice has sparked much debate amongst fans, some of which feel it is an extreme change.
Once the logistics of the Predalien were determined, the next challenge was actually getting the creature on set. As he has done in the past several Alien and Aliens vs. Predator movies, Alec Gillis stepped into the suits of many of the film’s creatures, including the Predalien. Given the larger size of the Predalien, the suit was considerably heavier. The tail was longer than the Gillis’ body, and required the use of crew member holding up the end via wire just to keep the suit balanced. These elements required solutions from Gillis and Woodruff that aren’t necessarily present on the standard Xenomorph warriors.
The cast and crew had to be careful that the press did not take unflattering pictures of the Predalien, as looking at a man in a suit will not have the same effect as seeing the same man under the scrupulous lighting conditions necessary for shooting a film. Greg and Colin Strause, along with Alec Gillis and Tom Woodruff, understood that the Predalien would look fearsome on film, but the effect could be quickly ruined if the wrong picture made its way into the hands of the expectant audience members.