Im guessing..

Spoiler: show

They are the reason everything happen in the first movie?

I've got a liberal arts degree, but I have a sneaking suspicion that Neal DeGrasse Tyson spent the night crying himself to sleep.

I actually thought it did!

Reeves also pointed out that the final scene on Coney Island shows something falling into the ocean in the background without an explanation. This may have been either the satellite owned by the fictional Japanese media company, Tagruato, or the creature itself. A company news piece on the Tagruato website mentions that a piece of the Japanese Government's ChimpanzIII satellite fell off into the Atlantic. Producers Bryan Burk and J. J. Abrams also revealed their thoughts on possible sequels to Entertainment Weekly. According to Burk, "The creative team has fleshed out an entire backstory which, if we're lucky, we might get to explore in future films". Abrams stated that he does not want to rush into the development of the sequel merely because the first film has been a success; he explained that he would rather create a sequel that is true to the previous film.[82]

A fourth film in the franchise, Overlord, has recently completed filming and is currently set for release in October 2018.

https://en.wikipedia.org/wiki/Overlord_(2018_film)

Plot[edit]

In 1944, two American paratroopers are shot down over Normandy in the midst of the D-Day invasion and they discover that the Nazis are using supernatural forces against them.