SCP-4975, The Cuckoo Clock

In its first phase the creature stays passive, observing the player from a distance and producing clicking sounds as it turns its head. Once it enters its second phase it becomes hostile and attacks by inflicting the Curse Clock effect. When that effect ends, the monster spawns behind the player and attacks. A player who cannot outrun it dies. Defeating it makes it disappear and drops a mysterious book, which should be opened with care, and the book can reset the creature to phase one while giving the Curse Clock effect.

SCP-4975, The Cuckoo Clock needs Geckolib on Forge. A server running it needs every connecting player to have it too. Its phase changes are controlled by a game rule named chuckooClockPhase2: it is set to true when phase two begins and to false while phase one is active. The mod was made by Zcoper with MCreator, and it is released under All rights reserved, so it is not open source. Forge files cover the 1.19.2 – 1.20.1 range, with the latest build 1.0.0 for 1.20.1, published 2026-06-10.