Stronghold Guardian

The idea is for a mob that is part of the structure of the stronghold. As an update to the stronghold, pillars could be added to the walls both as decoration and for the new mobs functions. Each pillar would be four blocks tall with a special stone block at the top and bottom and stone pillar blocks in between. When a redstone signal is applied to the bottom block, a stone mob will replace the stone pillars and try to attack the player. These could naturally occur through trip wires or skulk sensors. When no player is detected, the mob will pathfind to the nearest empty pillar and despawn and replace the pillar blocks. This would add more interest and challenge to the stronghold structures, and if the special pillar blocks were obtainable, could be used by the players in creative ways. Players could also interrupt the spawning of the new mob by breaking the pillars before they are activated, allowing for multiple strategies in dealing with them. It would also be interesting perhaps if they were slow but high in health and damage making them a more unique mob that can be escaped easily but hinders progress if not dealt with.