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One wouldn't think something so big would be able to hide so well, but that's exactly what this monster does. Being around 23 feet long and 16 feet tall, this creature mostly just hides in various places in Ice Sheet Lake.
It only ever seems to come out sometimes during the summer months for mating season. Its main hiding spots would almost be in plain sight. Very little difference can be seen between itself and the ice that covers the lake. It burrows into the hard ice that covers the lake and "fits" itself into the hole it creates. It waits until a creature(s) steps on it and then attacks them while they're on its back, conjuring up ice spikes to trap and injure the creature(s).
It is unclear whether they burrow deep enough to break through the entire ice layer that covers the lake, either way they never fall into the lake itself it seems, and any holes they may make quickly gets covered up again by the permafrost water beneath.