Picture of Giant Flashing LED Spider
Danger is my middle name and I wanted to make something cool and tech-y for the Halloween contest- we're budding engineers, so we figured we should be able to put together something cool.

What we came out with was this: a spider with eight LED eyes that flash on and off depending on the position of a couple of tilt sensors. It's perfect for looking innocuous, and then surprising passersby who brush by it, only to have it flash on at them.

We hung it above our dorm room door to scare visitors.

Step 1: Gather materials

Picture of Gather materials
You will need:
-2 Tilt sensors (pictured below)
-8 LEDs
-some fabric
-a hot glue gun
-solder and soldering iron
-a ping pong ball
-some wire
-some kind of cord
-batteries for your LEDs & a battery pack
-electrical tape