Sudo Code Modded Mobs for Indoor Spawning

- Every X ticks, search in a radius(sphere or box) of Z
- Choose random block from that array

if (Block != Material.AIR ) {
    if ((block.location +1 in Y) == Material.AIR) {
        if ((block.location +2 in Y) == Material.AIR) {
            //spawn zombie
        }else //find new random block and repeat
    }else //find new random block and repeat
}else //find new random block and repeat