There's a doll hidden in the open world area that appears to be of unknown species/race. Do we know what this is?
There are several other dolls in the game, but all of them are of known characters: Chief, the Pilot, the Weapon, a Grunt, the Librarian, the Arbiter, Sgt. Johnson, Spartan Locke, and The Harbinger. Map Genie's
interactive Halo Infinite map calls it an "Endless doll," but it doesn't look anything like the outline seen on the cylix at the end of the game.
On a different note, when going back through pre-release media for the game, I noticed a weird date in one of the trailers. There appears to be a date on a control panel in the Pelican cockpit in the original reveal from E3 2018. That date looks like 05.27.2560.
This closely matches the date shown at the beginning of the 2020 Gameplay premiere, which is 05.28.2020. And I believe that's essentially when the final game takes place as well. But in between the E3 2018 reveal and the E3 2020 gameplay reveal, we got the E3 2019 Discover Hope trailer, which got weird. When the Chief's armor is rebooting, there is a quick flash of dates corresponding to the creation and the latest update to the OS:
That second date is nearly a year and a half later than the dates from the other trailers. In the final game, the year of the second date is changed to "2559." It's definitely possible that "2561" in the Discover Hope trailer is a typo, but I'm pretty sure that 343 scrubs any officially released video like this for unintended reveals and I would assume that they also verify that a detail like this is accurate. Which leaves open the possibility that they flirted with setting the game later than they actually did.