Slyther

The Slyther was a tentacled blob-like creature native to Skaro. During the 22nd century Dalek invasion of Earth, the Black Dalek used a Slyther to guard the Bedfordshire mines at night, where it killed and ate anything it found. After attacking a small group of humans consisting Ian Chesterton, Larry Madison, Wells, and Ashton (killing the latter), Ian hit it with a rock, causing it to fall down a pit to its death. (DW: The Dalek Invasion of Earth)