The hengrauggi, or hengra, was a predatory creature native to the ice planetDelta 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.
In 2258, a hengrauggi attacked a drakoulias as it was running for James T. Kirk, who was marooned on Delta Vega. After disposing of the drakoulias, the hengrauggi commenced with chasing Kirk itself.
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)
The hengrauggi was designed by Neville Page. Page also designed the monster for the J.J. Abrams-produced film Cloverfield, which shares some similarities with the hengrauggi. Its head was inspired by a prolapsed rectum.  According to the Blu-ray, it is a sea creature.
It was nicknamed by the crew as "Big Red", though it was also often referred to as a "lobster monster". In a tie-in flash game produced by Esurance for the film, it was referred to as a "snow slug". Its short name comes from the film's audio commentary.