Alice Coltrane
From Tardis Wiki, the free Doctor Who reference
Alice Coltrane was one of Donna Noble's friends in a parallel world. Though no one else at their Christmas gathering could see the Time Beetle, Alice stared at Donna Noble's back and told her, "There's something on your back."
Even as the Webstar attacked London from the sky, Alice's remained transfixed on Donna's back, terrified.
At one point beforehand, she claimed to have seen the ghost of Earl Mountbatten at the Boat Show. (TV: Turn Left)