Myrka (The Lost Dimension)

A Myrka was placed in the Pacific Ocean within a perception filter by the Sixth Doctor to protect Horlak's tribe of Silurians. Centuries later, in 1886, the Myrka attacked a ship captained by Madame Vastra, causing her along with Jenny Flint, Rose Tyler and the Ninth Doctor to be shipwrecked on an island. The Doctor noted that the Myrka was doing its job "a little too enthusiastically." (COMIC: The Lost Dimension)