Robot
LEGO: Flyer Delivering Robot
hat tip Make:
K'nex Tic Tac Toe Robot
see also:
Instructables - Tic Tac Toe Robot
Brick Throwing Robot
Oreo Separator
Soft-Boiled Eggbot
hat tip Make:
Robot Worm (Continuous Wave Reristalsis)
hat tip Adafruit Industries
Robot Spider Web
hat tip Adafruit Industries
Jumping Robot
hat tip Core77