This shows you how to make a simple, respectable, and casual Dr. Octopus costume. I've seen some amazing "Doc-Oc" costumes out there, and while this costume lacks their pizazz, it does allow you to casually walk through doorways and hang with your friends without the worrying about large arms hitting people or knocking things over. This costume good for Halloween, but great for crowded scifi/comic conventions.
The best part about this instructable is it made from ALUMINUM CANS!! This is because recycling is very important to me, and also, there are few things as cheap as aluminum cans.
Step 1: Needful Things
Soda cans (14 should do, but you may need more if you have a short coat and need longer arms)
Trench coat, or any coat that goes down to your knees
Googles or sunglasses
Spiderman Action figure (Optional, but I think you want to use one anyway. You can probably find a cheap used one at a flee market, or Comic convention)
Silver metallic spray paint
Tin Snips or a pair of kitchen shears you don't mind trashing
A square Ruler (an adjustable one is helpful, but not necessary)
A punching tool (I used an Awl, but a nail and hammer'll work just fine)
Hot Glue Gun
Step 2: Prepping Your Cans
Now that you have a sufficient number of empty soda cans (I cannot stress how important it is that they are empty), we can begin transforming them into the unstoppable robotic arms we all know and love. Set aside four cans to be your claws.
Start by using your square ruler to make a mark 2 1/4 inches above the bottom of the can. Continue this all around your can until you have a dotted line, then draw a solid line over it.
Now carefully cut along the line with your pen knife. While doing this, I accidentally deviated from the line a few times. If you make the same mistake, you can trim the bumps with you tin snips.
Finally, take your awl (or nail) and punch a hole through the center of can halves.
Step 3: Making Claws
Take the four cans you set aside and draw a line around the top part of the cans where it starts to taper (exact spot marked on photo). Also, mark the mid section just like you did with all the other cans.
Now use you pen knife to cut the top off. Next, take your tin snips and cut out claw fingers so they taper outward. Then, fold the flaps of the can that are not fingers into the can where no one will see them. Finally, put a bend in the middle of the fingers, making a knuckle, and then fold the fingers outward at the bases. Try not to bend the aluminum back and forth too much, or it'll snap.
Step 4: Painting
Cover your arm segments with silver spray paint! Let them dry.
You can also draw a black line at the base of each claw to make look more like a joint than a solid piece of aluminum.
Step 5: Putting Them Together!
Cut four 5' sections of string. You probably won't need all 5', but it pays to be safe. Tie a big knot in one end, then slide your claw onto it.
Now here is where it gets interesting. Tie a slipknot about where you think the next segment/can will rest, but make sure the lower part of the string is the adjustable end. This way you can adjust the distance between the knot and top of the claw if you need to once you slide on your next can. Remember, the knots will need to be a little higher for arm segments made from the top of the can.
Once you're satisfied with the placement of your knot, lock it in place with hot glue. Continue these steps until you've reached a desired length; I chose 6 segments including the claw.
Now that you have an arm that meets your personal standards, determine how low you want your arms to dangle, then make a loop at waste level, and slide it onto your belt.
Step 6: Final Touch
Add the trench coat, and goggles, or sunglasses depending on your preference. Just let the arms dangle below you coat, carry a martini glass and make comments about how you can't operating heavy machinery while intoxicated.
Your technically done. If you opted to purchase the Spiderman action figure, insert it into one of you claws, and hot glue them shut onto it. Hopefully this will communicate your costume to everyone whom only saw the movie.
Also, if your arms are jiggling more than you'd like, you may run a strip of clear scotch tape down one side. This will slightly restrict it's movement, and prevent you from sounding like a junkyard wind-chime.