Who or what is this … ?

just watched it, its one of the crew but not sure. he appears to be armed

*SPOILER ALERT*

A person wearing a backpack XD 

Ha!  ^  @Neomorph 

You're right, looks like a person sitting down with a backpack on his back. Perhaps one in the crew taking a rest? Seems like they walked up a hill?

hes not resting, by the looks of the trailer he has broken off from the main group either to scout ahead or maybe for a pee but in the trailer he is constantly moving

Well, he appears to be sitting down. Perhaps the one who trampled on the fungi and got the "spore" in his ear?

@Neomorph

I have reread your post several times and I just don't see anything that resembles a spoiler....

Can you help a brother out....?

 I think he's being sarcastic 

@ninXeno426

I know...I just owe Neomorph some grief   :)

He was fanning out from the main group. Easily seen in the trailer.