Most commuters have seen everything when it comes to battling in and out of the capital every day - but not many have come face-to-face with a giant polar bear on the Northern Line.

The 8ft-long fully animated creature was not only spotted on the London Underground but also on Hampstead Heath and the South Bank.

Two puppeteers from the West End show War Horse controlled the movements of the bear, which was built to promote Sky Atlantic's new "Arctic-noir" series Fortitude, from inside.

The thriller, set in a fictional town with 3,000 polar bears for every 713 residents, stars Stanley Tucci, Michael Gambon, Sofie Grabol and Christopher Eccleston and launches on Sky Atlantic on Thursday January 29.

Sky Atlantic director Zai Bennett said: "We wanted to bring a realistic polar bear to the streets of London to give people an up-close experience of what it must be like to come face-to-face with one of the biggest, but uncredited stars of our new show."

A team of 19 prop specialists spent eight weeks designing and building the realistic replica animal.  There were six to eight people working on the costume at any one time, using over 60 types of materials which included 90 square foot of sheet fur.  

The finish of the head was achieved using a process known as flocking, which involves feeding individual strands of nylon hair into the skull and then using an electrostatic current which causes the hairs to stand up on end. Over the top of the flock longer hairs are individually hand punched into place in directions seen in natural growth. 

Did you see the bear?