Discovery Channel has released the first clip from its upcoming documentary about the elusive giant squid, which can grow to a monstrous 26 feet in length and is likely the source of the Nordic legend of the kraken. Discovery Channel will air the footage -- the first time the giant squid has ever been seen in its underwater habitat -- in the special “Monster Squid: The Giant Is Real,” on Sunday, Jan. 27 at 8 p.m. ET.