Dragon's teeth

"Dragon's Teeth" is the nickname Alliance marines have given to the huge spikes that geth use to turn human corpses (and living victims too) into Husks. Their function resembles ancient methods of execution by impalement. The name comes from Greek mythology, specifically Jason and the Argonauts; when a field was sowed with the teeth of a dragon, each tooth sprang up as a soldier.

The dragon's teeth in Mass Effect are comprised of a tri-pod like support, and a metal spike that retracts when not in use. It is possible that this retraction also serves as a trap, activating to impale anyone who approaches the tripod, as dragon's teeth are often found in use where there have been no geth to operate them.

The devices convert the muscle, organs and water content of a corpse into cybernetic parts, then reanimate the body, turning it into a simple-minded Husk that attacks anyone who gets close enough. The technology behind the dragon's teeth spikes is a mystery. It doesn't resemble any other geth technology and deploying the spikes seems to be a lot of effort for a minimal result, though their psychological effect on soldiers is undeniable.



Speculation
Nobody knows where these spikes came from, as they don't resemble any other geth technology, and are found in systems far removed from geth space. Shepard also found a cache of dragon's teeth that had been buried on Trebin with no hint of who put them there or when. This might be ancient technology that the geth have appropriated. However, Husks resemble the mechanically-infused tissue constructs envisioned by Shepard during interaction with the Prothean Beacons. It is speculated that this is Reaper technology, and one of their methods of conquest or even indoctrination.