SCP-736 is an anomaly affecting the Saturnian moon Iapetus. For brief periods generally lasting several days, Iapetus' orbit is spontaneously altered by measures of eccentricity, orbital period, or both. The orbit of Iapetus returns to its documented state after these spontaneous changes. Models of temporary orbits almost entirely consist of Iapetus undergoing orbital decay, and in most scenarios is projected to collide with Saturn (and, depending on the projection, other Saturnian moons) at some point within the next 150-300 years. These projected orbits are all in direct violation of mathematical models and both classical and relativistic physical principles, which do not predict a decay in the orbit of Iapetus due to tidal effects or gravitational radiation.