Introduction: April Fools Screaming Lizard Shipping Container

About: Just a guy who likes building things for my family.
This Instructable will teach you how to build a fake animal shipping container box to scare your friends or kids.

My kids had been wanting to get another pet for some time so I thought I would use that to my advantage for this April Fools Day prank.

I built a small shipping container box that looks like it has a live lizard inside.  Little did my kids know that it was actually a box with a spring loaded bar that makes them think a lizard is jumping out of the box as they open it. 

When they start to open the lid of the box it looks like the lizard is jumping out of the box and a motorcycle horn goes off.  It's a lot of fun.  Watch the video to see all of the fun and how startled they were.

This project is extremely fun and extremely loud.  I took this to work and had a lot of people ask  to see what was inside.  I didn't get video of them, but I don't think they would have given me permission to use it anyway.

Step 1: Tools and Materials


The tools I used on the project were as follows:
  • Table Saw
  • Band Saw
  • Scroll Saw
  • Oscillating Belt Sander
  • Drill press
  • Cordless drill
  • Hacksaw
  • Screwdrivers, wrenches and pliers
  • Clamps
  • Vise
  • Sanding block
  • Screwdrivers and wrenches
  • Soldering Iron

Not all of the tools in this list are required, but may make the construction much easier.  Your build may need more or less than what I show.  This may also vary based on the material that you use for your project.

  • 1/2" thick plywood
  • 3/4" thick plywood
  • 12 volt dc motorcycle horn - cheap one overseas from Ebay
  • On/Off pushbutton switch
  • Rolling lever switch
  • Aluminum bar stock - 1 " wide x 1/8" thick
  • Various screws, washers, and nuts
  • Electrical wire for the horn circuit
  • Hasp for box lid
  • 2" hinges for box lid
  • 1" hinge for throwing lever

NOTE: If you plan on using any tool for a project please make sure you are familiar with the tool and all of the dangers associated with it. If you are not familiar with a tool then you should ask someone who is to show you the proper way to use it. A lot of communities have classes at local colleges on the proper use of tools and machinery. There are also local woodworking clubs that offer classes at very reasonable rates for beginners. I highly recommend using these resources for your safety and for the most efficient use of the tool.

Always wear eye and hearing protection.
Always work safe with the proper safety equipment and guards on your tools.

Step 2: Design the Box

I wanted the box to be big enough to look like it would be holding a good sized lizard.  I started the design of the box using Autocad  software by Autodesk so I could visualize the box and the proportions.  I was most familiar with this software.  I then imported the 3D file into Autodesk 123D and applied wood material to the solids.  I have attached the Autodesk 123D file for download.

I ended up with a box that is 10-3/4 inches tall, 10 inches deep, and 18 inches long.

The top of the box is hinged.

There are air holes in the box that help people think there is a live animal in the box.

I made a fake shipping label showing the contents of the box and that it came from Australia.  More on this in future steps.

Step 3: Cut Out and Assemble the Box

I used left over material on the box where I could.  I also wanted the box to look a little rough like a real shipping box so I wanted the pieces to be a little rough or beat up where possible.  A perfect box without any signed of being shipped half way around the world is a sure giveaway that it isn't really a shipping box.

Start building the box by making the two end pieces.  The end pieces are 1/2 inch plywood with 1-1/4" x 1-1/4" pieces glued around the outside.  The sides and the bottom of the box are attached to these 1-1/4" x 1-1/4" pieces with #8 1-1/4 inch deck screws.  The 1-1/4" x 1-1/4" pieces are cut down from some left over pieces of 2x4's.

Next attached the end pieces you just made to the bottom of the box.  The bottom piece is 1/2" thick plywood as well.  To keep things from moving while you attach the ends to the bottom, clamp them in place.  Make sure you pre-drill the holes so you don't end up splitting the 1-1/4" square pieces.

Now add the 1-1/4" square pieces between the end pieces.  Clamp them in place to keep everything in alignment.

Now attach the front and back pieces.  Again, clamp these in place while you pre-drill the holes and put in the screws.

Now you just need to add the top (lid) of the box.  In order to get this to sit flush with the top of the box you will need to notch out the back piece to recess the 2" wide hinges.  The hinges are centered at 4 inches in from each end of the lid.  I used a band saw to cut out the notches for the hinges.

Here is a list of the wood pieces for the plywood portions of the box:

End pieces - 1/2" thick x 8-1/2" wide x 9-1/2" tall

Front and back pieces - 3/4" thick x 18" wide x 10" tall

Bottom piece - 1/2" thick x 8-1/2" deep x 18" long

Top piece (lid) - 3/4" thick x 10" deep x 18" long


Step 4: Build the Lizard Spring Mechanism

This mechanism releases a spring that shoots a plastic lizard up out of the box as the lid opens.  The lizard sits on a hinged bar with a spring attached.

The trick here is that the lizard release has to happen after the lid opens to a certain point or the lizard will be launched into the under side of the lid and then fall back down into the box instead of going out of the box and making people run for cover.

I used 1 inch by 1/8 inch aluminum flat pieces for most of this mechanism.

Cut a piece of the aluminum flat about 8 inches long and attach it to the 1' hinge with two holes as shown in the pictures.  I used 2 #8x1/2" machine screws to attach it to the hinge.

I added a small rectangular piece of 3/4" plywood to the inside of the box to attach the hinge to.  I needed a way to get the hinge a short distance away from the front wall of the box so it could rotate all the way to the vertical position.

I also added a small rectangular piece of 3/4" plywood to the inside of the box to attach the spring to.  I didn't want to take a chance on drilling through the front of the box for the screw to anchor the spring to.

I also added a piece of 3/4" plywood to the inside of the box on the left side of the lever that throws the lizard.  You will see more on this in the next step for the release mechanism.

Step 5: Make the Release Mechanism for the Box

I'm sure there are many ways to make a release for the lever that throws the lizard out of the box.  I had several different sketches I came up with, but this is the one I decided to use.

Basically you should watch the video and look through the pictures to see how everything goes together.  In a nutshell, the three pieces of 1" wide aluminum flat pieces are attached together at one end.  The piece that is twisted 90 degrees goes up to attach to the angle bracket on the lid of the bod.  The other short piece goes up at approximately 45 degrees to the right and it attached to the back piece of the box.  The long horizontal piece goes through the piece of plywood and holds the lever in place.  As the lid if lifted the horizontal piece moves to the left and releases the lever.

You will need to cut the end of the piece that holds down the lever to the proper length once you have everything in place and you know where you need the release point to be.

Step 6: Add the Motorcycle Horn and Battery Pack

The motorcycle horn I used for this was a cheap 12v horn I purchased of of Ebay.  I initially tried a car horn, but had trouble getting enough electricity (amps) out of batteries to actually make the horn work properly.  I settled for the motorcycle horn as it will work off a small battery and it is smaller in size, but still very loud.

I just used two AA battery packs that hold 4 batteries each.  I connected them in series to get 12 volts dc.

I used a lever switch that was open in the compressed position.  When the switch is released it closes the circuit and the horn goes off. 

The battery packs are connected in series with the pushbutton switch, rolling lever switch, and motorcycle horn.

Step 7: Test Out All of the Parts

Make sure you test your box parts a number of times so you can make sure it is working consistently when being triggered.  You only get one shot at scaring someone with this so you will want to make sure it works properly.

You may want to take the batteries out while testing it so people at your house don't hear the horn going off and start looking to see what is making the noise.

When I had the box at my office we told people to shut the door in the office they were opening the box.  A lot of the other people there thought the horn noise was coming from the parking lot.

Step 8: Shred Some Newspaper

I used shredded newspaper to help hide the parts inside the box.  It looks like bedding material and is hard to see through.  I think it adds to the suspense of the box so people wonder what is hiding in that shredded newspaper.

When the lever arm releases some of the newspaper goes flying and people don't know what is trying to jump out at them.

I think this prank would work fine even without the rubber lizard.  The sudden movement of the newspaper and the extremely loud horn is what scares most people.

Step 9: Add a Shipping Label and Caution Sign

I think this is the part that really helps pull the prank together.  The person opening the box sees that it comes from Australia and that the box has a lizard inside.   The label even tells them that it comes from an exotic animal farm and to use CAUTION.  I think it lets their imagination get the best of them.  I think it did for my kids.

I told my kids to read the label to see what was in the box.  They don't tend to read labels before opening things otherwise.

I have attached the shipping label I created so you can edit and print your own.  The label is in Paint Shop Pro format.

I have also included a "Caution! Live Animals" picture with an up arrow if you would like to put on on your box as well.  Download the picture at full resolution for best results.

Get creative and see what you can come up with.  If the person you are pranking doesn't like snakes then modify the labels to suit your needs.

Step 10: Set Up and Pull the Prank

Sometimes April Fools Day pranks are a little easier to pull off if you do them a day or two earlier.  My kids try to pull pranks on me (with the help of my wife) every year, so they are always aware that day is coming up.

I had my wife tell the kids that I was bringing something home from work they would like so they were looking for something when I got there.  I had my wife get the video camera ready so we wouldn't miss anything.

I set the box down and had them read the shipping label to see what was inside.  Once they read the label, tell them to slowly open the lid on the box and to be careful.  It's just good, clean fun.

Once you pull this prank on your kids see if they want to do it to their friends a well.  You can have a lot of fun over a few days with this.  I took the box to my office and we had a lot of fun there as well.

Make sure you have people opening the box in a position where they will not fall off a chair when they get startled.  Also make sure no one is in the way of the box lid as it opens.  We want people to have a fun April Fool's day and not get hurt.

Have fun with it and let me know if you have done something similar!

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