Trick pencil holder w/ hidden compartment.

thingiverse

Young Inventors Take Note: Clever Pencil Holder Conceals Hidden Surprise Eager to outsmart the ordinary, one resourceful student crafted a clever pencil holder with a secret compartment. This ingenious device was designed and built as part of an exciting 8th-grade engineering project. The project's goal was to create something both functional and clever, and this talented student definitely succeeded in achieving that goal. The pencil holder looks like any ordinary desk accessory at first glance, but it has a hidden surprise waiting to be discovered.