The Silicate Harvester is a rare sight on Hoxxes - a truly docile beast that neither runs nor attempts to kill you. In fact, it seems mostly oblivious to anything apart from its relaxed hunt for delicious trace elements and microscopic crystals found in the Hoxxes soil. They are large and friendly, their reverberating song an uncommon but welcome respite from the relative surrounding chaos of Hoxxes.
— Miner's Manual Description
The Silicate Harvester is a passive mob found in Dense Biozone, Fungus Bogs, Radioactive Exclusion Zone. It makes its way slowly across the map using it's tentacle-like arms to sift through the terrain. It is used to complete two Achievements. It was introduced in Update 14: Feature Creep. The patch notes for the update do not mention Fungus Bogs. They were either introduced there later or their presence in the Fungus Bogs was not included in the patch notes.
Slowly sifts through the map looking for its food, throwing up small clouds of dust while doing so. It is completely oblivious to damage and its surroundings, and won't react to either.