Who is argos in The Odyssey?
Argos was Odysseus' faithful and beloved dog that waited for twenty years for his return - only to see him, recognise him through his begger's disguise and then die (from lack of strength and old age) before he could reveal Odysseus' true identity: : As they were talking, a dog that had been lying asleep raised his head and pricked up his ears. This was Argos, whom Odysseus had bred before setting out for Troy, but he had never had any enjoyment from him. In the old days he used to be taken out by the young men when they went hunting wild goats, or deer, or hares, but now that his master was gone he was lying neglected on the heaps of mule and cow dung that lay in front of the stable doors till the men should come and draw it away to manure the great close; and he was full of fleas. As soon as he saw Odysseus standing there, he dropped his ears and wagged his tail, but he could not get close up to his master. When Odysseus saw the dog on the other side of the yard, dashed a tear from his eyes without Eumaeus seeing it, and said: : "Eumaeus, what a noble hound that is over yonder on the manure heap: his build is splendid; is he as fine a fellow as he looks, or is he only one of those dogs that come begging about a table, and are kept merely for show?" : "This hound," answered Eumaeus, "belonged to him who has died in a far country. If he were what he was when Odysseus left for Troy, he would soon show you what he could do. There was not a wild beast in the forest that could get away from him when he was once on its tracks. But now he has fallen on evil times, for his master is dead and gone, and the women take no care of him. Servants never do their work when their master's hand is no longer over them, for Zeus takes half the goodness out of a man when he makes a slave of him." : So saying he entered the well-built mansion, and made straight for the riotous pretenders in the hall. But Argos passed into the darkness of death, now that he had seen his master once more after twenty years. : Homer, Odyssey Book 17
When Odysseus comes home, the first creature he's actually happy to see is his dog, Argos, who has been waiting for 20 years for his master to come home. Since the suitors had taken up his courtyard, Argos was forced to sleep outside on a dung heap, which was the only heat source he could find. I suppose he symbolizes Odysseus' joy to see his home again, because Odysseus' is ecstatic to see him again.
In Homeric poetry, the Greeks are referred to as Argives (as in, "people of Argos") or Danoi (as in, "sons of Danaus"). Danaus was the mythological ancestor of Perseus, legendary founder of the civilization of Mykenai. Argos was the capital of Mykenai. So, basically, throughout the Iliad and Odyssey, the Greeks in general are referred to as Mykenaians, though the Spartans, Ithakans, etc. were also present.