I don't know if you guys knew this about me, but in addition to my writing I'm also a professional puppeteer. That's my day job, so you can imagine that of all the wonders fantasy movies create, I have a special fondness for the creatures. Puppetry has changed drastically over the years for these fantastic animals -- the creations have become so vividly life-like that they're now indistinguishable from the actors. This week we'll learn about the evolution of these techniques, and just what goes in to bringing your favorite fantasy beasts to life.

Stop-motion
In stop-motion, you take an armatured puppet and move it ever-so-slightly for every frame of film. The work is painstaking and takes hundreds of hours to complete a few seconds worth of screen time, but the result is other-worldly. Perhaps the most famous puppeteer, Ray Harryhausen, took the novelty of stop-motion and constantly pushed the limits of what was possible in movies. He first hit the screen with Mighty Joe Young in 1949, but in the Seventh Voyage of Sinbad (1958) he really shows off what he can do, combining traditional stop-motion with live action. You can still see this technique in use today in movies like Coraline (2009).

Hand puppets
Hand puppets are (of course) anything you stick your hand in, like Jen (Jim Henson) and Kira (Kathryn Muellen) from The Dark Crystal (1982). Puppets like this have an immediacy to them because their puppeteers are watching monitors that show exactly what the camera is seeing, giving them the ability to adjust framing instantaneously. The disadvantage is that you have to hide the puppeteer somehow -- which works great when you're in Yoda's house on Dagobah, but becomes more challenging when the Muppets Take Manhattan. You can see fine examples of hand puppetry in everything from Splinter (Kevin Clash) in Teenage Mutant Ninja Turtles (1990) to Gizmo (Frank Welker) in Gremlins (1984).

Body puppets
If you have to put your whole body inside a puppet to make it work, then it's a body puppet. The distinction between a body puppet and a costume is defined by displacement. In a costume, every body part lines up with the actors. But in The Adventures of Elmo in Grouchland (1999), for instance, Big Bird's (Caroll Spinney) left hand is stuffed and strung, while Spinney uses his hand to control the moving mouth and eyes. Body puppetry is used to good effect with Rock Biter in The NeverEnding Story (1984) and Ludo (Ron Mueck) in Labyrinth (1986). The advantage to using a puppet this way is that the live actors can respond to the same thing the audience sees in real time, enhancing the illusion. But it's more of a challenge for the puppeteer, who's trapped underneath a heavy costume, typically with restricted vision.

Animatronics
This technique started off as an extension of hand and body puppets. Cable controls, much like on bicycle brakes, would extend from the puppet to an extra puppeteer who was responsible for blinking eyes or wiggling ears. Jim Henson pushed this technique in Labyrinth, creating hybrids like Hoggle (Brian Henson / Shari Weiser), a costumed actor with an animatronic head. Later, the controls began to utilize computers so that a single performer could run an entire character. Now you'll see amazing, fully-realized creatures like Stan Winston's wolves in Lady in the Water (2006). Animatronics allow puppets to escape the constraints of their own strings, as it were.

CGI
Computer Generated Images have become so commonplace that they don't surprise anyone anymore. These characters exist entirely online and are manipulated somewhere between stop-motion, body puppetry, and animatronics. In some cases the cgi character is animated in real time with a mitt that's almost like a hand puppet, in other cases he is created through a process more akin to drawn animation. The advantage here is that you can manipulate the world in any way you want, as when Yoda flies around with a lightsaber. Granted, I think that his was a case when the technique overwhelmed the character, but mileage may vary. The disadvantage many forms of cgi have is that any live actors on screen are acting to empty air.  In other cases, like for The Two Towers' (2002) Gollum (Andy Serkis), the performer uses motion capture which translates his movements into a computer world. One of the reasons that Gollum worked so well is that Andy Serkis was acting on the same set, in real time, as the other performers.

You might think Hollywood's growing reliance on CGI would make a puppeteer like myself cringe, but some directors, like Guillermo del Toro are moving back to real time puppetry when they have to interact with humans, as in Pan's Labyrinth (2006), because they find they get a more compelling performance. To me, it's a moot question, because the thing that all of these forms have in common is that they require a human hand, in one form or another, to bring the character to life. This gets to the heart of fantasy and puppetry; both forms take imagination and give it life.

Mary Robinette Kowal is the winner of the 2008 John W. Campbell Award for Best New Writer and a professional puppeteer. Her first novel Shades of Milk and Honey is being published by Tor in 2010.