//copiado da net
    public void freezeEntity(Entity en) {
        net.minecraft.server.v1_8_R1.Entity nmsEn = ((CraftEntity) en).getHandle();
        NBTTagCompound compound = new NBTTagCompound();
        nmsEn.c(compound);
        compound.setByte("NoAI", (byte) 1);
        nmsEn.f(compound);
    }