The CW has posted a new extended trailer for this year’s crossover episode of The Flash and Arrow. The two-hour event will feature the debut of Hawkman and Hawkgirl. This is also the start of DC’s Legends of Tomorrow. The first part debuts with The Flash on Tuesday, Dec. 1st, followed by the second part with Arrow on Wednesday, Dec. 2nd. Both episodes premiere at 8 p.m. EST on their respective nights on The CW.