Mover pear
From Tardis Wiki, the free Doctor Who reference
Mover pears were shiny red fruit from the Hyades Cluster.
Due to Gallifreyan trading missions being licensed to go to any point in space and time, the markets of Prydos sold mover pears. Once bought, a mover pear would follow its owner around until it was eaten. (PROSE: The Garden of Evil [+]Loading...["The Garden of Evil (novel)"])