Naughty Dog remains mum about the details of "The Last of Us 2" after its announcement at the PlayStation Experience in December 2016, but players continue to speculate about the highly anticipated game.

One of the fan theories that has been going around for a while is the possibility of Ellie's pregnancy in the sequel of the action-adventure survival horror game that was released in 2013. The speculation was first discussed in one of the posts on PlayStation Forums, where a fan noticed an Easter Egg of "The Last of Us 2" in "Uncharted 4."

The Easter Egg features a poster of the upcoming game that showcases a seemingly pregnant woman donning a gas mask that hides her face. The fan claims that it could be an older version of Ellie, who could be pregnant with a child.

The post claims that other people will argue that the pregnant woman could not be Ellie, since she does not have to protect herself from the virus because of her immunity. But the fan states that Ellie might be protecting the unborn child inside her womb who may not be immune to the virus, or she might be protecting herself from a poisonous gas.

There are also reports claiming that "The Last of Us 2" will focus on an entirely new setting, since the cordyceps infection was spread all over the world. According to Trusted Reviews, there could be a chance to see Ellie and Joel travel across the globe and meet new characters from New York, London, or Moscow to help end the virus invasion. The game developer has yet to confirm if any of the fan theories will turn out to be true.

Meanwhile, Naughty Dog previously revealed that "The Last of Us" game director Bruce Straley will not return to direct the sequel because of a hiatus.

"Bruce recently decided to take some much deserved time off after shipping two critically acclaimed games in the last few years," the game developer said in a statement back in December. "He's looking forward to returning to the studio soon and jumping back in on his next project."

The release date of "The Last of Us 2" on PlayStation 4 is expected to be revealed soon.