Joseph Lawrence Greene was an American author of specultive fiction, who dabbled in comics. Greene is best known for creating the first Robot T-Rex that Batman battled on the Isle That Time Forgot.
Greene's contemporary, Don C. Cameron (also a prolific author) created the Trophy Room concept in the Batcave, in which Greene's Mechanical T-Rex eventually became a part of, along with Bill Finger's Giant Penny. These two objects are alost always present anytime the Batcave is shown.