Puppetmaster

If you were looking for the trope about people who control puppets, look here; for people who control other people, see here. For the sci-fi novel by Robert A. Heinlein, look here. And for the trope formerly known as the novel, look here.

An author/perpetrator of an Alternate Reality Game is called a puppetmaster. In most cases, many puppetmasters are involved in a game, because there is a good bit of work to be done, widely divergent work. Such tasks include burying clue boxes on a GPS coordinate, having cryptic cards printed and distributed, or playing an in-game character for a recorded message.

The most widely known Alternate Reality Games are the A.I. tie-in "The Beast" and the Halo tie-in "I Love Bees." It is not a coincidence that the owner of record for almost all of the Web sites in "The Beast" had the surname "Gheppetto". (Further, both The Beast and I Love Bees were produced by the same team: 4orty2wo.)
"The Puppet Master" is also an alias used by Phillip Masters, a reoccuring supervillain in the Marvel Comics fictional universe. He mentally controls his victims by sculpting their likeness from a special radioactive clay.

Lastly, Puppet Master was a cult horror film from Full Moon Pictures which spawned nine sequels of varying quality.