The latest teaser for the upcoming "Arrow"/"Flash" crossover features Falk Hentschel's Carter Hall -- better known as Hawkman -- attempting to to explain that Vandal Savage is one super villain that won't be easy to take down.

"The final moments of 'The Flash' have a pretty big jaw-dropper and we pick up those threads in 'Arrow,'" the shows' EP Andrew Kreisberg said of the 2-part story. "Then we do some things with the characters from 'Arrow'...that are pretty epic and major."

The crossover starts December 1 on "The Flash" and continues December 2 on "Arrow" before spinning out into 2016's "Legends of Tomorrow" miniseries.