Building upon the character 's surprise introduction in " Asylum of the Daleks " , " The Snowmen " introduces Clara as the Doctor 's new companion , though ultimately it would be a third version of her character that would travel with the Doctor starting with " The Bells of Saint John " . In addition to Clara , " The Snowmen " also introduces a redesigned TARDIS , revised title sequence and theme music , and sees changes to the Doctor 's costume . The special was produced in August 2012 , with location filming in Newport , Wales and Bristol . It received final ratings of 9 @.@ 87 million viewers in the UK , becoming the fourth most @-@ watched programme of Christmas Day . " The Snowmen " was met with mostly positive reviews from critics , most of whom received the introduction and character of Clara well . However , some felt that Grant and McKellen were underused as villains or the plot was slight because of the focus on characterisation .