Giant Polyp of Vargon III

These "giant polyps" are an alien form of life that was unexpectedly discovered on the planet Vargon III.

Biology
Nothing is known about these creatures other than that they seem to dwell in tunnels created by volcanic vents, and that their planet was believed to be a barren, life-less world; until the polyps came up and "snared" the first human explorers.

Appearances

 * "A Walk in the Dark", by Arthur C. Clarke (1950)