Alvega Earthworm
From Tardis Wiki, the free Doctor Who reference
The Alvega earthworm was a species of massive earthworm-like invertebrates native to the planet Alvega.
An Alvega earthworm was utilised during the battle for Alvega when the Controller ordered the worm to attack the three Dalek ships on the ground at the time.
A fourth ship that had tunnelled to the core of Alvega encountered the worm, but it was finally killed by the Daleks. (COMIC: The Amaryll Challenge)