Mouth of Sauron at Erebor ?

[The Might]

As I was reading through another thread, I suddently came across this quote:

'Then about a year ago a messenger came to Dain, but not from Moria - from Mordor: a horseman in the night, who called Dain to his gate. The Lord Sauron the Great, so he said, wished for our friendship...
'As a small token only of your friendship Sauron asks this,' he said: 'that you should find this thief,' such was his word, 'and get from him, willing or no, a little ring, the least of rings, that once he stole. It is but a trifle that Sauron fancies, and an earnest of your good will. Find it, and three rings that the Dwarf-sires possessed of old shall be returned to you, and the realm of Moria shall be yours for ever. Find only news of the thief, whether he lives and where, and you shall have great reward and lasting friendship from the Lord. Refuse, and things will not seem so well.'~The Council of Elrond

Could it be that Mouth of Sauron was sent to Erebor to deal with the Dwarves ? Are there any indications that he was the one sent ? Or was it someone else ?

[Kuruharan]

I think it was more likely a Nazgul from Dul Guldur. It was a long way for the Mouth to travel three times, Dul Guldur was closer. The reaction of the Dwarves was also rather profound for an ordinary Man (because that is essentially what the Mouth was).

[Boromir88]

I always thought it was a Nazgul too (although it can't be for certain). I'll get to that more in a bit. Aye, but first:

The reaction of the Dwarves was also rather profound for an ordinary Man (because that is essentially what the Mouth was).~Kuru

But the Mouth wasn't really your ordinary man. When we are first introduced to him he is actually described as being like a Ringwraith:

The rider was robed all in black, and black was his lofty helm; yet this was no Ringwraith but a living man.~The Black Gate Opens

Though the Mouth truly was a man, he was in some ways like a Ringwraith. However, I doubt the Mouth could inspire the fear into people the way Ringwraiths did.

The wraiths relied heavily upon fear:

Their peril is almost entirely due to the unreasoning fear which they inspire (like ghosts). They have no great physical power against the fearless.~Letter 210

This messenger certainly put fear in the dwarves:

'At this we were greatly troubled, and we gave no answer. And then his fell voice was lowered, and he would have sweetened it if he could.'

'At that his breath came like the hiss of snakes, and all who stood by shuddered.'

'Heavy have the hearts of our chieftains been since that night. We needed not the fell voice of the messenger to warn us that his words held both menace and deceit.'~The Council of Elrond

It could be that the Dwarves were scared just in the fact that they denied Sauron's offer of peace and they were troubled about what was to happen next. However, I don't think so, as emphasis always seems to be placed on the 'fell voice' of the messenger. Also there is the 'hiss of snakes' which we know is another distinct quality of the Ringwraiths.

Also, the messenger was out for information. It wanted to find out about 'the thief' (Bilbo) and where he was with this ring he had 'stolen.' At this time it were the Ringwraiths who were going around trying to gather information about 'Baggins' and 'Shire.' So, I definitely agree with Kuru that it was a Ringwraith who was the secret messenger.

[Legate of Amon Lanc]

I'd agree with Kuruharan&Boro on that this "horseman in the night" might be a Ringwraith. Boro's "hissing" points are quite good, and also Kuru's thoughts of Dol Guldur being much closer to Erebor than Mordor.

I went a little bit further and done a little exegesis to support this theory.

As we know, Gloins speaks of this messenger to Dain at the Elrond's Council; Gloin says that the messenger will come

for the third and the last time, as he said, before the end of the year.

This means that it was three times the same one, just to make matters clear (unless the Dwarves could not distinct one messenger from another, which is not impossible, a guy in black and a guy in black look the same, but on the other hand you don't send three different negotiators to Erebor if you have one who already was there and this is his job).

In Unfinished Tales, there is written, that

the second greatest [ringwraith], Khamul, the Shadow of the East, stayed in Dol Guldur along with his messenger

Well, I'm sorry for the unexact quotations, but if the second guy (a Ringwraith as well) is called "a messenger" and stays in Dol Guldur, this would speak for Boro's idea and imply that this pal of Khamul might very possibly be the one we seek.

If someone needed to verify if the Ringwraith were able to be at Erebor, there are the datums. Remember that it was almost at the start of their quest for the Ring-bearer, so were they "on-line" at the time the messenger came to Erebor?
Gloin says that first time the messenger came "a year before" the Council, as he puts it, so let's say september to november 3017. This would imply that immediately after receiving the information from Gollum, Sauron sent this messenger to the "scene of murder", Erebor (of course he did, being it such a grave matter as the One Ring). At this time, the Nazgul were certainly "free of duties" to do this. The second coming, however, is quite obscure. Gloin says just that he returned without answer, but does not say when. If our "horseman in the night" indeed was a Ringwraith, it would have to happen before June 3018, when the Witch-King and the other Ringwraith set out from Mordor to meet with Khamul and his messenger (according to UT). This happened after Sauron received the message of Gollum being captured by Aragorn, which, according to UT, was some time around April 3018. According to Gloin, the messenger said that he'd come before the end of the year. Sauron's choice of sending the Nazgul out was improvised and quick in response to the events at that time, thus, when the messenger came, he still counted on that the third time (as he said, before the end of 3018), he will return and ask about the whereabouts of the Ring and it's bearer. He did not know that at the moment, the whereabouts of the Ring would be already known because of speeding up the events with Sauron's response to the capture of Gollum by Aragorn.
So it is indeed possible that this messenger was a Ringwraith, and we also came up to the dates of the messenger's coming

So, to be precise, the only thing which might stand against the theory of the messenger being a Ringwraith would be that the Ringwraith were something like a "last resort" for Sauron, and he didn't want to use them because the fear they produced was too great. However, this fear was just the thing Sauron used (um, as always). Also, it was problem for the Ringwraith to cross water, however, this would be possible on oars or whatever in the Wilderness. They had also problem with orientation in daylight - but this would speak FOR the Ringwraith theory, since the messenger could have traveled at night - and, Gloin says, that he came in the night - and what man would not camp outside Erebor and wait for the dawn until negotiating! Also, in the night, his identity could not have been revealed - so that no one would know he was a Ringwraith!

[Rune Son of Bjarne]

I cannot remember what I initially thought this messenger was, probably a wring wraith, but I must say that I see no evidence for it.

Fell voice: I am fairly sure that the Mouth of Sauron was not very lovely to listen to, any human can have a fell voice

Hiss of Snakes: Now this is something that I assoisiate with the Nazgul, but I sertainly do not see it as proof! and it did only make people shutter, the Nazgul is known to have a more severe effect on their soroundings! And it was only those who heard him that was affected, not the people of Erebor in genneral. Like one can be moved by the words of another man, so can the appearance and sound of him make you shutter.

Heavy have the hearts: Yes of course! They stand between to opptions 1. the eternal wrath of mordor, or 2. betraying a friend. Who would not have heavy harts?

It could very well have been a Nazgul, but it might as well have been some sort of living messenger. Yes these things could indicate that it was a Nazgul, but for some reason I doubt that Tolkien would descripe a living messenger from Mordor as a real cheerful and lovely chap' !

[The Might]

well, I hate answering my own question, but I remembered I overlooked one also important aspect of the story when asking.
as Lieutenant of Barad-dur, Mouth of Sauron clearly was charged with dealing with internal business, and taking care of the matters in the Dark Tower.

However, I have just found some quotes that make me believe it was just an ordinary emissary, and not a Ringwraith:

Yet all his ordinary spies[size=-1] and emissaries could bring him no tidings. ~ UT, The Hunt for the Ring[/size]

So, because these emissaries, such as the one he sent to Erebor, didn't manage to bring tidings of where the "thief" and the Ring were:

At length he resolved that no others[size=-1] would serve him in this case but his mightiest servants, the Ringwraiths, who had no will but his own... ~ibid[/size]

By the time he took this decision, the emissary had already visited Erebor, so I doubt it could have been a Nazgul, because Sauron hadn't decided on using them yet.

And I have another reason that makes me think that the Nazgul never went to Erebor. Considering the story in the UT we can see what effect the presence of a Nazgul has, effects much more devastating then the words of the messenger at Erebor. People fled from their homes in Rohan when they went to Isengard, fear went before them and lingered behind them. These are clearly not the effects the messenger has.
The hearts of the Dwarf chieftains are heavy, but not because of the messenger himself, but because of the message. They knew all what the messenger was talking about, and they all knew the might of Sauron - that is in my opinion reason enough to have a heavy heart. This quote is in my opinion very useful:

We needed not the fell voice of the messenger to warn us that his words held both menace and deceit; for we knew already that the power that has re-entered Mordor has not changed, and ever it betrayed us of old. ~The Council of Elrond

Also, had they passed that way, we should have had reports from the Elves as well, since Legolas was present.

As Rune very well points out, the fact he had a "fell voice" or "hiss of snakes" do not mean he was necessarily a Nazgul.

So my conclusion: this was just an "ordinary" emissary, that "[size=-1]could bring him no tidings."[/size]