Easy to do. /ubbthreads/images/graemlins/grinning-smiley-003.gif
Either scrounge or go to Radio Shack and buy one of those 1.5 volt motors ($2?), a rheostat*, an on/off switch*, a spool of wire, a battery tray that'll hold one "AA", "A", "C" or "D" battery. The larger batteries last longer. Go dumpster diving behind any shopping center for a piece of poly foam. If you find a sheet of plastic or coroplast, grab that for the wings, otherwise cut a plastic lid off coffee can, butter container, old sign or whatever.
Cut the foam to any shape you want.
Cut a hole or holes for the battery tray, motor, switch* and rheostat*.
Wire battery tray, rheostat*, on/off switch* and motor.
Glue the parts inside the foam body.
Glue a makeshift wing to the motor shaft.
Paint the thing if you want too.
*These pieces are optional*.
Here is a rabbit I made:
The rheostat is nice because you can control the speed of the motor with it. You don't really need an on/off switch if you don't mind taking the battery in and out to start and shut it off.
I placed my battery tray in a box and it uses four "AA" batteries for weight. Without the extra weight, I'd need to clamp it to a tree or tie it down to keep it from taking off into the next county. /ubbthreads/images/graemlins/laugh.gif
If you know of places where people illegally dump stuff, you could probably find nearly everything you need. Old broken toys often have battery trays, switches and motors. Toys, TVs, various electronic junk will have wire and other parts that you can use. I'm a real scrounge. /ubbthreads/images/graemlins/blush.gif /ubbthreads/images/graemlins/laugh.gif
Even if you have to buy everything, I doubt if it'll cost $10 total. If you don't mind scrounging and dumpster diving you could build it for nothing. /ubbthreads/images/graemlins/grinning-smiley-003.gif