Umpty Um
From Tardis Wiki, the free Doctor Who reference
An Umpty Um was a creature in the short story 'The Terror of the Umpty Ums. The Terror of the Umpty Ums was a short story written in lockdown and was put in Doctor Who: Adventures in lockdown. In one page of this story the doctor says. "Of course they are, everyone's scared of them. and the sontarans, and the slitheen, And of course, The Umpty Ums."
The Doctor also says "oh there the worst. Nothing scares me like the Umpty Ums."
The name Umpty Ums, was made because of a reference to the Doctor Who Theme tune. (umpty um, umpty um, umpty um, umpty um.)