gistfile1.js

system.listenForEvent(ReceiveFromMinecraftServer.PlayerAttackedEntity, 
    function(en) {
        setTimeout(
            function() {
                let entity = en.data.attacked_entity;
                let entityActor = Actor.fromEntity(entity);
                let entityHealth = entityActor.getAttribute(7);
                let entityName = entity.__identifier__.substr(11, 64);
                entityName = `${entity.__identifier__.substr(10, 1).toUpperCase()}${entityName}`;

                let playerEntity = en.data.player;
                let playerActor = Actor.fromEntity(playerEntity);
                let playerHealth = playerActor.getAttribute(7);
                let playerNetwork = playerActor.getNetworkIdentifier();

                console.log(`PlayerAttackedEntity => ${entityName}, ${entityHealth} ❤, ${playerNetwork.getAddress()}`);
            }, 10
        );
    }
);