A fake entity.

FakeEntity.java

package com.comphenix.example;

import java.util.Collections;
import java.util.List;
import java.util.UUID;

import org.bukkit.Bukkit;
import org.bukkit.Location;
import org.bukkit.entity.Player;
import org.bukkit.plugin.Plugin;
import org.bukkit.scheduler.BukkitTask;

import com.comphenix.protocol.reflect.accessors.Accessors;
import com.comphenix.protocol.reflect.accessors.FieldAccessor;
import com.comphenix.protocol.utility.MinecraftReflection;
import com.comphenix.protocol.wrappers.WrappedDataWatcher;
import com.google.common.base.Preconditions;
import com.google.common.collect.Lists;

public class FakeEntity {
    /**
     * Retrieve the entity counter field used to generate a unique entity ID.
     */
    private static final FieldAccessor ENTITY_ID = Accessors.getFieldAccessor(
            MinecraftReflection.getEntityClass(), "entityCount", true);
    
    public List<Player> observers = Lists.newArrayList();
    
    private Location clientLocation;
    private Location serverLocation;
    
    private int entityId;
    private String name;
    private String uuid;
    private WrappedDataWatcher watcher;
    private boolean changed;
    
    // Update task
    private BukkitTask task;
    
    public FakeEntity(Plugin plugin, Location location, String name) {
        this.clientLocation = Preconditions.checkNotNull(location, "location cannot be NULL");
        this.serverLocation = clientLocation.clone();
        this.name = Preconditions.checkNotNull(name, "name cannot be NULL");
        this.uuid = UUID.randomUUID().toString();
        this.entityId = (Integer) ENTITY_ID.get(null);
        this.watcher = new WrappedDataWatcher();
        this.watcher.setObject(0, (byte)0);
        
        // Increment next entity ID
        ENTITY_ID.set(null, entityId + 1);
        
        // Background worker
        Bukkit.getScheduler().runTaskTimer(plugin, new Runnable() {
            @Override
            public void run() {
                updateEntity();
            }
        }, 1, 1);
    }
    
    public void addObserver(Player player) {
        notifySpawnEntity(player);
        observers.add(player);
    }
    
    public void removeObserver(Player player) {
        WrapperPlayServerEntityDestroy destroy = new WrapperPlayServerEntityDestroy();
        destroy.setEntities(new int[] { entityId });
        destroy.sendPacket(player);
        observers.remove(player);
    }
    
    private void updateEntity() {
        // Detect changes
        if (changed) {
            for (Player player : observers) {
                notifySpawnEntity(player);
            }
            changed = false;
        
        // Update location
        } else if (!serverLocation.equals(clientLocation)) {
            broadcastMoveEntity();
            clientLocation = serverLocation.clone();
        }
    }
    
    private void notifySpawnEntity(Player player) {
         WrapperPlayServerNamedEntitySpawn spawned = new WrapperPlayServerNamedEntitySpawn();
         spawned.setEntityID(entityId);
         spawned.setPosition(serverLocation.toVector());
         spawned.setPlayerName(name);
         spawned.setPlayerUUID(uuid);
         spawned.setYaw(serverLocation.getYaw());
         spawned.setPitch(serverLocation.getPitch());
         spawned.setMetadata(watcher);
         spawned.sendPacket(player);
    }
    
    private void broadcastMoveEntity() {
        WrapperPlayServerEntityMoveLook move = new WrapperPlayServerEntityMoveLook();
        move.setEntityID(entityId);
        move.setDx(serverLocation.getX() - clientLocation.getX());
        move.setDy(serverLocation.getY() - clientLocation.getY());
        move.setDz(serverLocation.getZ() - clientLocation.getZ());
        move.setYaw(serverLocation.getYaw());
        move.setPitch(serverLocation.getPitch());
        
        for (Player player : observers) {
            move.sendPacket(player);
        }
    }
    
    /**
     * Destroy the current entity.
     */
    public void destroy() {
        task.cancel();
        
        for (Player player : Lists.newArrayList(observers)) {
            removeObserver(player);
        }
    }
    
    public int getEntityId() {
        return entityId;
    }
    
    /**
     * Retrieve an immutable view of every player observing this entity.
     * @return Every observer.
     */
    public List<Player> getObservers() {
        return Collections.unmodifiableList(observers);
    }
    
    public Location getLocation() {
        return serverLocation;
    }
    
    public void setLocation(Location location) {
        this.serverLocation = location;
    }

    public String getName() {
        return name;
    }
    
    public void setName(String name) {
        this.name = name;
        this.changed = true;
    }
}

Why does this not work in 1.8 Spigot servers? It works fine 1.7.10 and below. Any help in solving this would be appreciated.

@blazedaf It's becasue the Wrappers have changed.

Is there any updates for the 3 wrappers used or the new names?

any chance to update it for 1.15.2? :P