Spawn any living mob with whatever status effects you want. Works with Vanilla and Custom mobs and effects from other mods.

For more advanced version check out this
https://www.curseforge.com/minecraft/mc-mods/entity-manager

• Pick any mob, add one or more effects, and set the level, duration (set -1 for infinity) and spawn chance for each one.
• An in-game GUI you open from a button on the title screen, with a searchable mob list, a preview and info panel.
• Export and import configs as .json files through your system's file explorer.
• Nothing's set up by default, so installing the mod doesn't change anything until you configure it.
• Effects get applied once, when a mob first spawns or loads.
• If the file's broken it gets ignored and logged, and the game won't crash.
• When using this mod on a server, the player does not need to have it installed.

• Stored in config/entity_effects.json. It loads on its own and reloads when you edit it, no restart needed.
• On a dedicated server You have to install the config Yourself, because there is no way to change it in game.

Requirements

Fabric, Minecraft 1.20 to 1.20.4. Needs Fabric API.