a new item and mechanism

something that can be built like the conduit or the beacon, now it would attract mobs or repel them , like manipulating the spawn rates as well as actually attracting or repelling existing mobs, for example mobs that have a head item would be attracted by the heads added to the new structure, or maybe totem like structures , for example a creeper would be repelled by an ocelot totem in the structure and a zombie would be attracted by a villager totem or so