Avatar: The Way Of Water - 22 WTF Moments

Probably the biggest surprise in the movie that was kept entirely out of its marketing is that Spider, the human boy living on Pandora since the events of the first movie, is actually Quaritch's son.

This is implied early on and outright confirmed later, that he was born on Pandora but couldn't be transported back to Earth due to a young child's inability to withstand cryostasis, at which point he was taken in by the Sullys.

While the film doesn't bother explaining who Spider's mother is, the prequel comic Avatar: The High Ground reveals that she was an RDA pilot named Paz Socorro, who died during the assault on the Tree of Souls in the first movie.

It's a pretty convoluted reveal, albeit clearly an attempt by Cameron to further parallel Jake and Quaritch with their respective family turmoil.