This creature is called a Gulper and it's part of a game concept I've been developing (the game is called BOL - Ball Of Light).

In it, the hero is trapped in an underground realm with very limited visibility (so advancing is very slow and careful).

The Enemies are all hunters that use senses other than sight - introducing (hopefully) interesting game mechanichs, so the Gulper has three forms in the game - hatchling, juvenile and adult. The Hatchlings is harmless, the juveniles are aquatic hunters and the adults are a danger on land and the water. The aduklt lays submerged with it's crest peeking from the water (looking like water vegitation), ilumminating and attracting prey. When a gulper senses vibration close enough, they burst from the water and use their tongue to ensnare and drag their prey to their huge mouths and swallow them whole - in one gulp...