"Pretty Little Liars" ended the first half of season 6 with a shocker as it was revealed that "A" is Charlotte, who, before her transition, was actually called Charles and is Alison's brother. But after the 5-year time jump in the second half of the season, executive producer Marlene King revealed that there will be a new villain in town who will be even more lethal than Charlotte.

Speaking to Hollywoodlife at New York Comic Con, King said, "The new big bad—I won't say if it's a he or a she. We think it's a he right now, but you never know."

The producer added that the new villain is "more lethal" and is not into playing games.

"The new big bad has an agenda and will not stop at anything before that agenda is taken care of," she said.

In the first look clip for season 6B, Aria (Lucy Hale), Hanna (Ashley Benson), Spencer (Troian Bellisario), and Emily (Shay Mitchell) appear to be scared of the new big bad as they come running into Alison's classroom and telling her that "he's back." The new villain must be someone who can inflict a lot of pain and damage, as his arrival in Rosewood caused the girls to come together to warn Alison about him.

Expect the new season to be full of changes, as 6B will see the girls after they have graduated from college. Fans will see that Ali has become a teacher, Aria is now a writer, Hanna is working in fashion, Emily is a bartender and Spencer is working in politics. Some of the girls will also be walking down the aisle.

At Paleyfest, King said that season 6B will be "lighter in some ways because we're starting a new mystery. In terms of the finale, the producer said that the new season's final episode may be their best finale yet.

"We probably saved the best for last in terms of what that final finale will be," she said. "We know what the big reveal in that final episode will be and who it will be."

"Pretty Little Liars" 6B premieres on Jan. 12, 2016 on ABC Family.l