Bukkit

The default pre-version 2.0 config is shown below:

angels:
    spawn_rate:
        how_many: 5
        how_often: 400
        max_per_world: 50
    worlds:
        - world
    freeze_time: 100
    weapon: DIAMOND_PICKAXE
    drops:
        - COBBLESTONE
        - STONE
    angels_can_steal: true
ice_warriors:
    spawn_rate:
        how_many: 3
        how_often: 400
        max_per_world: 25
    worlds:
        - world
    drops:
        - ICE
        - PACKED_ICE
        - SNOW_BLOCK
cybermen:
    spawn_rate:
        how_many: 3
        how_often: 400
        max_per_world: 30
    worlds:
        - world
    drops:
        - REDSTONE
        - STONE_BUTTON
    can_upgrade: true
always_use_leather: false

The spawn_rate sections sets Angel, Cybermen and Ice Warrior spawning options.

• how_many sets how many monsters to spawn each time.
• how_often is the time period (in server ticks - 20 ticks = 1 second) between spawn attempts.
• max_per_world is the maximum number of the monster that can be alive at one time.

The worlds section allows you to list the worlds you want the monsters to spawn in.

drops sets a list of items that drop when the monster is killed.

always_use_leather sets whether Cybermen and Ice Warriors spawn wearing leather armour (true) or the correct armour (false) for when using the resource pack.

Angel specific

freeze_time is the length of time (in server ticks) that the Angels remain motionless for.

weapon sets the item that will kill a Weeping Angel.

angels_can_steal sets whether the Angels can steal your TARDIS Key - requires the TARDIS plugin to be installed.

Cybermen specific

can_upgrade sets whether the Cybermen can upgrade players and villagers.