There is a cage north-east of the chapel that contains a random familiar each time a player would be near it. This was shown in a glitch that allowed a player to walk out of the Cosmic Altar and end up here. One theory could be that the cage keeps familiars that are "returned to the spirit plane" as when jumping down in a pool in Oo'glog to contain the familiar and stop its timer just to send it back to the player when they go out of the pool and start its timer again.