Mabel Pines

Mabel Pines was with her brother Dipper and their Grunkle Stan in the Mystery Shack when the Doctor's TARDIS clipped its roof and flew through its interior, following the Tenth Doctor telling Rose Tyler that they would be travelling "further than [they'd] ever gone before". (TV: Untitled)

Behind the scenes
Mabel Pines originates from the Gravity Falls series. Archival audio of her voice actor, is used during her appearance.