Endermen can move blocks. This is usually only a minor inconvenience because of their relatively low spawn rate. However, once you fully light up your world with torches, lanterns, or other light sources, Endermen become much more noticeable. Since most hostile mobs can no longer spawn in lit areas, Endermen make up a larger percentage of the remaining mob spawns.
Even though Endermen cannot spawn directly in torch light, they can still spawn:
After spawning, they can teleport into your play space and start rearranging your blocks.
!Grass block placed by an enderman in an improper place
You could disable mob griefing with:
/gamerule mobGriefing false
But this also disables behavior for many other mobs, including villagers, animals, and other non-hostile mechanics that players may still want enabled.
This plugin specifically targets Endermen and prevents them from mutating your world. This way you don't have to worry about disabling other mob functions that might be useful in farms and such.
Prevents Endermen from picking up blocks
Prevents Endermen from placing blocks
Gives Endermen a configurable chance to spawn already holding a block
33%Configurable scan radius for selecting held blocks
4 blocksWhen an Enderman spawns, the plugin scans nearby blocks within the configured radius around the spawn location. Any block contained in Minecraft's enderman_holdable tag can be selected, and the enderman will be spawned carrying that block. This way we can preserve the appearance and atmosphere of vanilla Endermen while preventing the terrain from being disfigured.