Ruby Gemstone Cluster
The Ruby Gemstone Cluster is an item with a "loot" icon when you mouse over it. "Looting" it will summon an Enormous Gyreworm, presumably because this is its tail, and you just tugged it. The Enormous Gyreworm drops the Ruby Crystal Cluster item which is the objective of Beneath the Surface.
Patch 4.0.3a (2010-11-23): Added.