In Game Config Screen

Open Mods → Mob Settings → Config to edit every option without touching the file.

• Each rule is shown as a plain sentence, like "Zombie drops 2 Diamond (25% chance)".
• Pick mobs, items, dimensions, biomes and tags from searchable lists instead of typing IDs.
• Attributes are filtered to the ones the chosen mob actually has, and each shows its allowed range and the mob's normal value.
• Extra drops and added spawns have a dedicated "..." data editor for item components (enchantments, custom name, damage, unbreakable) or entity data (equipment per slot with its own drop chance, custom name, persistence, and any other NBT), with copy/paste support for whole /give or /summon command text.
• Optional fields can be left blank, and the sentence shows the default they use.
• Hover any field for an explanation of what it does.
• Invalid entries are highlighted in red, so mistakes are easy to spot.
• The entry editor fits rules with many fields, even on smaller screens.

Everything is saved to the same config file, so you can mix the screen and manual editing freely.