Our robot consisted of two parts: one would pop up a gravestone and one would make floating knives move up and down. For our project, we originally attempted to use bluetooth to communicate between the two EV3 bricks, spending a large amount of time attempting this. However, no matter what we did, we could not get this code to work.

For the gravestone, we had a box of candies located right in front of the gravestone, hiding the gravestone attached to two large motors for rotating up and down. We also used the box to hide itself for a bigger "scare". The motors would be activated whenever the ultrasonic sensor would sense someone grabbing for a candy 30 centimeters or closer.

For the knives we used two NXT motors and a small lego piece which acted as a spindle. The string would then wrap up and down the piece, and give the appearance of the knive floating in mid air.