MCreator issue tracker has been migrated to GitHub.
Existing tickets have been migrated to GitHub. Please open new tickets on the GitHub tracker instead. If you do not have a GitHub account, all feature requests and bug reports from forums are still considered and checked by the maintainers.
We will consider adding this in the future. Right now, you can set mob to spawn in all your custom biomes by setting entity spawn list in biome creation but we will improve this.