With production set to start soon on the back-to-back filming of Avengers: Infinity War and Avengers 4, little details about the upcoming films (and specifically Infinity War) are coming to light through casting calls. Perhaps one of the biggest so far was the apparent confirmation of Captain Marvel in Infinity War, though other details are also spilling out.

The latest casting call for the film is seeking actors of a particular build to play aliens in the movie. Unfortunately, the details provided in the call don’t necessarily do much to narrow down which aliens are being used for the film.

The casting call, which was reported by Project Casting, is looking for both men and women who appear to be between 18 and 50 to play “aliens” for a “fun background role” in the film. The actors specifically need to be tall, and have a slender or athletic build. All ethnicities are encouraged to apply, though makeup and prosthetics will be used to create the alien look. The full casting call description reads as follows:

Aliens: We are now taking submissions to be considered for a fun background role on this upcoming movie. Looking for men and women, all ethnicities, who appear 18 – 50’s, who are TALL with a SLENDER or athletic build. MUST be comfortable being PAINTED (including on your face & any exposed body parts). Also looking for people willing to have prosthetics applied to their face, in addition to being painted. Bumps will be provided for makeup & prosthetic applications.

Filming is tentatively scheduled for April 5 & May 30- must be available for BOTH days with no conflicts. Must have an open & flexible schedule as you will be needed for multiple wardrobe fittings & makeup tests prior to the film dates.

If you fit the above description & have a FLEXIBLE schedule, send an email to MaryLou@CentralCasting.com with “ALIEN” in the subject line. Include your name, phone number, sizes & current photo(s).

A request for tall, slender aliens doesn’t really narrow down the specific race, given how many alien races have appeared at one point or another in Marvel’s comics. Some have suggested that the aliens may be part of an army that Thanos controls, but this may not be the case; the casting call is trying to fill extras for a “fun” role, which makes it sound more like something from just some off-world setting where the actors will appear in the background behind some of the film’s stars. It’s possible that the casting call is to fill background characters for a race that fans would recognize such as the Kree, but it’s just as likely that the characters will be more like generic “aliens” from no specific notable “race.”

If nothing else, the casting call at least gives a date for when filming of the scenes with these aliens is likely to occur. Hopefully, more light may be shed on the aliens and the scenes that they appear in closer to those dates.