Earlier today, Nintendo updated their official Youtube channel with a new trailer for Splatoon 2. The latest trailer features a look at the Holiday update for the game. The first free update will be available on November 23, which will be adding new gear and hairstyles as well as a new stage of Salmon Run. The second free update will launch later this December, which will include a brand new Ranked Battle mode called Clam Blitz.
Source: Nintendo
