SCP-3663 is a Keter Class anomaly also known as The Adventure of the Cardboard Box or The Tunnel Monster. SCP-3663 is a humanoid entity constructed primarily from cardboard, adhesive tape, and twine. SCP 3663 is fully capable of movement and vocalization via an unknown mechanism, and has proven to be semi-sapient. The interior of SCP-3663 contains crude cardboard and paper models of all major human organs, with colored wool representing blood vessels and the nervous system. SCP3663 does not requ