MythicMobs

Iris has support for Mythic Mobs 5.

Download MythicMobsMythicCraft Minecraft Marketplace

Iris Entities

You can spawn mythic mobs in custom biomes by following this format, More info Entities.

{
    "type": "CAT",
    "surface": "LAND",
    "specialType": "MythicMobs:JumpingSpider"
}

The "type": "CAT"does not actually change anything. It just makes sure Iris accepts the entity.

As seen here, to make Iris spawn a mythic mob, you'll need to create a new Iris entity file with specialType, where you prefix the name with MythicMobs:

VSCode will autocomplete Mythic Mob names installed on the server if you are using Iris Studio, too!

MythicMobs RandomSpawns

See the MythicMobs wiki:

• Skills -> Conditions

• And specifically Skills -> Conditions -> Biomes