From Destinypedia, the Destiny wiki
A Proxy is a Vex-simulated entity created by the Infinite Forest to lead other simulated units. Some are created by Panoptes, Infinite Mind to control nearby units and protect the Infinite Mind, while others act as Daemons to halt any intruders into the Forest.
Proxies have some degree of self-direction, as some have been seen to break free from Panoptes's control and wreak havoc across the Infinite Forest.
List of appearances