No, that's not a typo. It's a Geiger counter built in the style of H. R. Giger. It started off as a joke a friend posted on Twitter:

If I ever go to an alien planet, I'm bringing a Giger counter. #ThingsILearnedFomSciFIMovies

...and ended up as a really creepy-looking Geiger counter.

This is the third version I've made of this. The first was auctioned off at a charity event. The second went to Phil. This one, I'm keeping.

And, yes, I know that's not how it's pronounced. Just go with it.

Step 1: Materials

a 1/2 scale skeleton
a Mightyohm Geiger counter kit
1/2" (12cm) flexible conduit / wire loom
four 1/2" 4-40 (12mm M3) standoffs and screws (ideally black)
black duct tape (optional)
low-temperature plastic (e.g. Instamorph, Friendly Plastic)
black cable ties
epoxy
flexible wire (a couple lines salvaged from some ribbon cable works well)
dark metallic spray paint (e.g. Rustoleum Carbon Mist)
black spray paint

Tools

soldering iron & solder
drill
rotary tool with cutoff wheel
pliers
cutters
compressed air / canned air

Step 2: Assemble the Geiger Counter Kit

Build the Geiger counter according to the instructions, with the following exceptions:

connect the LED using about 8" (20 cm) of wire
pull the middle pins from J5 and use it as a strain relief for the LED cable.

Once you're sure the Geiger counter is working, paint the underside black and (optionally) cover the top with black duct tape, leaving VR1, the Geiger tube, the batteries and the mounting holes exposed.

You can also touch it up a bit with a black marker if you like.

Step 3: Disassemble the Skeleton

Unscrew everything and pull it apart. You'll only need the ribs, skull and 4 lumbar vertebrae.

Step 4: Cut the Skull

Cut the face off the skull. Don't worry too much about accuracy. You'll be filling in the gaps with plastic later. The intent is to get the remainder of the skull to fit down on the ribs.

Note: Don't glue it in place yet.

Step 5: Assemble the Vertebrae

Glue the vertebrae together.

Fashion a tail out of low-temperature plastic and glue that onto the narrow end.

While you're at it, you might want to glue together any loose connections between vertebrae on the rib-cage and fill in the screw holes.

Step 6: Cut and Paint the Conduit

Cut 6 pieces of conduit: 4 x 10" (25cm), 2 x 16" (40cm).

Spray paint dark metallic.

Step 7: Fit the Vertebrae to the Ribs

Cut off the bumps on the end of the ribs and drill holes to fit the bumps on the wide end of the vertebrae. If you want something a bit more durable, you can drill a couple holes and insert pins to strengthen the connection.

Note: Don't glue it yet.

Step 8: Drill Out the LED Hole

Drill a 3/16" (5mm) hole in in back of the skull.

Use a rotary tool to hollow out the inside of the skull a bit.

The LED should fit snugly in the hole, with the dome sticking out slightly. Once you've got it to look right, remove the LED again.

Step 9: Mount the Geiger Counter Board

Screw the standoffs onto the top of the Geiger counter board.

Put a blob of low temperature plastic onto the end of each standoff.

Put the Geiger counter board into the rib cage face-down and press firmly.

Once it's cooled, glue the blobs and standoffs in place.

Step 10: Attach the Skull to the Ribs

Thread the two longer pieces of conduit through the gap between the clavicle and the first rib on each side.

Mount the skull on the ribs.

Fill in the gaps around the skull with low temperature plastic, blending it in with the contours of the skull.

Once it's cooled, take it apart and glue the plastic into place.

Note: make sure the top of the skull is still removable. You'll need to access the inside of the skull to install the LED.

Make a post out of low-temperature plastic and mount it inside the skull. You'll need this later to hold the conduit in place.

You can sand down the plastic a bit to even out the bumps but, if you do, take a heat gun to the surface to polish it up.

Step 11: Painting

Remove the Geiger counter board and screw the screws back into the standoffs.

Glue the vertebrae onto the rib cage. You can use a couple cable ties to hold it together while the epoxy sets. From this point on, the Geiger counter board is going to be difficult to manoeuvre in and out of the assembly.

Use compressed air to clean any dust off the assembly.

Spray paint the assembly dark metallic. A couple coats should do. Hanging it on a wire hanger for painting and drying seems to work well.

Step 12: Final Assembly

Re-mount the Geiger counter on the standoffs.

Remove the top of the skull. Install the LED.

Slip the ends of the conduit into the rib cage and secure with cable ties.

Replace the top of the skull.

Slip the 4 smaller pieces of conduit into the gaps around the Geiger counter board. The exact arrangement isn't important. Whatever looks good.

Step 13: Using the Giger Counter

The power switch is hidden behind the conduit. Switch it on, hold it by the spine / handle, and go hunting for radioactive sources. Background radiation will cause it to beep occasionally.

Things containing a lot of potassium are mildly radioactive. I used a bag of potassium bicarbonate to test mine.

You can also get check sources from United Nuclear. A 5uCi Cs-137 disk will cause the Geiger counter to tick over nicely.