Supervisor Greene is an olive green Mister Handy model robot with a personality modified into that of an archetypical game show host. He, along with the two other supervisors, White and Brown, have much more advanced "cognitive processors" than the typical Mister Handy, which give them distinctive personalities derived from their creator, Dr. Edward Gray's, favorite television show characters. Greene offers limited merchant services akin to a general goods trader.
Greene will almost always be found tending the settlement's mutfuit orchard, and will from time to time engage in conversation with the other supervisors.
Performing his role as a game show host, Greene will attempt to reward the Sole Survivor with a "brand new" (actually a rusted out) car for resolving Graygarden's water crisis, although he will instantly offer a "cash prize" of 100 caps instead. Passing a speech check can increase the reward to 150 caps, another speech check increases it to 200 caps, then a final speech check can increase it to 300 caps.
Greene is a general goods merchant. He can also be assigned to specific merchant stalls if those are built at Graygarden; although he will not move to man them, he will still offer their full inventory.