The hengrauggi, or hengra, was a predatory creature native to Delta Vega. It had three sets of limbs, two used for running and another smaller hand-like set. It had hundreds of eyes. They also had a protrusion which served as a whip which they could use to grasp their prey. They were capable of traveling and attacking from underwater.
The hengrauggi ultimately chased Kirk into a cave, where it wrapped its whip-like protrusion around Kirk's leg and proceeded to pull Kirk towards its mouth. Before it could, however, it was repelled by Spock wielding a lit torch. (Star Trek)
- Star Trek's Beast Master Reveals How to Create a Monster - a Wired news article on the design of the lobster creature