Underwater

The Underwater is a special members-only room located beside the Hidden Lake. It can only be accessed by following the Giant Squid's shadow in the game Puffle Rescue. After a penguin has followed the shadow, the penguin gets in this room and can then come back whenever they like if they get the Moss Key Pin. Although there are no games to play in this room, the game Puffle Rescue leads to it.

Cave Expedition
This room was also available during the Cave Expedition. It was a members-only room. There was a free Coral Reef Background attached to a rock. The background is no longer there and has been replaced by the Moss Key Pin, which is available in the exact same spot.

Trivia

 * Both times it was open, it had a free item. The first time in January it had the Coral Reef Background, and now it has the Moss Key Pin.
 * It is the second permanent member room. The first was the Volcano.

SWF

 * Underwater during Cave Expedition
 * Underwater