The Pika
The Pika (/ˈpaɪkə/ py-kə; archaically spelled Pica) is a small mammal (nonfiction), with short limbs, very round body, rounded ears, and no external tail.
Whistling hare
It is also known as the "whistling hare" due to its high-pitched alarm call when diving into its burrow.
Failed expeditions into the the burrow
Several expeditions have entered, and failed to return from, the Pika's burrow.
Tuttle Expedition
Richard Tuttle famously assembled the Tuttle Expedition -- a crack team of post-Cubists and early Abstract Expressionists -- paying them handsomely to "Seek the Pik", as he put it.
The expedition descended in high hopes, but no one returned to tell the tale.
John Brunner declined an invitation to join the expedition, and later wrote a book about the dreams and premonitions which led to his decision.
Bonaparte's Gull
The Pika and Bonaparte's Gull are mortal enemies, and will attack each other on sight.