The Cryptic Castle Monster is a giant, skeleton-like creature with blue flames surrounding its face.
The Cryptic Castle Monster appears at the end of the normal mission's path of Cryptic Castle in Shadow the Hedgehog. It is immune to damage and cannot be killed. It chases Shadow down a set of three grind rails. In order to escape from it, Shadow must perform 180s or use the boost rings to stay ahead of the monster. The first boost ring is located on the left rail and the second is on the right rail. However, if the player fail to escape and allowing the monster to touch Shadow, he does his falling animation and dies.
- The creature appears to be of mysterious origin, as neither Eggman nor Amy seem to know what it is or why it's there.