Instructables author Honus has posted this excellent tutorial on how he built an Animatronic Horus Guard Mask from Stargate. The detail on his build is amazing - a fantastic blend of art and technology. The heart of the build is an Arduino-based motion control rig, controlling 5 servos that move the bird head and the fans on the side. The video below shows the mask in action.
Also check out Honus' other build: Predator
If you're interested in something a little... creepier, check out these animatronic babies:
Also check out Honus' other build: Predator