Recently, a new "billboard" advertisement went up, broadcasting the party, which will be taking place from April 21 to May 4 on the Island. During the Wilderness Expedition, Club Penguin members will be able to unlock the Sasquatch costume.
The advertisement above shows the Sasquatch of Club Penguin holding a makeshift fishing rod with a fish on the end of it, showing his survival instincts and ability to thrive in the wild. There is a suspicious penguin lurking in the bushes, perhaps being incited by the Sasquatch's capability and independency.
Oddly, the Sasquatch is shown for the first time without the Beta Hat in this image. He usually wears it when being seen on Club Penguin, so perhaps he takes it off when in his natural habitat.
Nevertheless, I think this is a brilliant sneak peek at the new expedition and a very clever way to promote it.