Monsters Influenced by The Eater of Worlds in your Maps have (0.8-1.2)% chance to drop an item with an Eater of Worlds Implicit Modifier

What this record tells you

This is a suffix modifier available from level 73. Its listed spawn tags determine which item families can naturally receive it.

Positive spawn weight means the modifier is eligible for that tagged item family. A zero weight blocks it for that tag. Weight is relative—not a simple percentage by itself.