The biggest creature in Subnautica Below Zero is the Sea Emperor Leviathan. This massive leviathan is the largest known creature in the game, and is truly a sight to behold. Measuring in at an impressive 30 meters long, this behemoth is sure to leave a lasting impression on any player who comes across it. While its size may be intimidating, the Sea Emperor Leviathan is actually a docile creature that poses no threat to players. In fact, this leviathan can even be befriended, and will provide helpful assistance during your underwater adventures.