Uses of Interface

Packages that use Entity
The root package of the Bukkit API, contains generalized API classes.
Classes used to manipulate the voxels in a world, including special states.
Interfaces for non-voxel objects that can exist in a world, including all players, monsters, projectiles, etc.
Interfaces for various Minecart types.
Events relating to when a block is changed or interacts with the world.
Events relating to entities, excluding some directly referencing some more specific entity types.
Events relating to players.
Events triggered by various world states or changes.
Classes involved in manipulating player inventories and item interactions.
Classes relevant to loot table manipulation and generation.
Multi and single purpose classes to facilitate various programmatic concepts.
Spigot-specific entity events.