Their kids, Wednesday and Pugsley, will be voiced by Chloe Grace Moretz and Finn Wolfhard–the latter is actually in IT: Chapter One and IT: Chapter Two, so that reference in the trailer has an added layer.
Nick Kroll will voice Uncle Fester in this iteration of The Addams Family.
Oscar Isaac is on board as Gomez Addams and his lovely wife Morticia (she of the IT jokes) will be voiced by Charlize Theron.
Bette Midler will voice Grandmama and Allison Janney will voice a reality TV host in the upcoming movie.