infer that, from Montresor's perspective, the huge golden foot in the coat of arms symbolizes Montresor himself, and the snake with its fangs "imbedded" in the heel of the foot symbolizes Fortunato. Snakes, ever since the biblical story of the Garden of Eden, have been associated with treachery, and Montresor is convinced that Fortunato is guilty of some kind of treachery toward him. The foot crushing the snake in the coat of arms foreshadows Montresor's murder of Fortunato.

The fact that Montresor describes this coat of arms to Fortunato moments before he kills him implies that he relishes the idea that he knows something that Fortunato does not. Montresor enjoys having power over Fortunato—both in knowing this and in taking his life.

The family coat of arms also suggests that Montresor is a very proud man. The fact that the foot is golden ("d'or") implies that his family has a rich heritage, and Montresor convinces himself that he is acting to honor that heritage by taking revenge upon someone who has supposedly acted to undermine it.

The family motto, "Nemo me impune lacessit," translates to, "No one provokes me with impunity." This emphasizes the idea that Montresor is a very proud man. His pride has been injured by something that Fortunato has done, or at least by something that he thinks Fortunato has done, and this seems to be his sole motivation for murdering him.

Fortunato appears to be acting disingenuously when he asks Montresor about his family coat of arms and motto. He regards Montresor as a member of a lower class then himself and probably has asked many such disingenuous questions during their relationship with the sole intention of hurting Montresor's feelings. He apparently believes that Montresor has no coat of arms or motto. Montresor has been lying to Fortunato consistently since they meet on the street, so there is no reason to think he is telling the truth when he describes his coat of arms.

A huge human foot in gold—such a design on a shield would seem bizarre, surrealistic, or comical. Poe probably wanted the reader to realize that Montresor was only kidding Fortunato. The motto, Nemo me impune lacessit, meaning "Nobody injures me with impunity," is, of course, appropriate, but it seems almost too appropriate. Montresor must be taking advantage of the fact that Fortunato is drunk to make the man look like a fool. Montresor is telling him what his coat of arms and motto would be if he had a coat of arms and a motto. Fortunato is not only drunk but probably does not even understand Latin, so it is especially ironic that he answers, "Good!" when Montresor is virtually predicting what is soon going to happen to him.

Montresor himself has been doing a little drinking along with Fortunato, so his rather odd behavior, including showing Fortunato his trowel and claiming to be a Mason, is understandable. Also Montresor has been under pressure to get Fortunato off the street and down below; and now he is experiencing relief because he knows he has his victim in his power. Montresor has a rapier concealed under his cloak. He can kill the unarmed Fortunato any time he wants—although it would be preferable to lead him to the site when he intends to wall him up.

The name, Montresor, in French, means "my treasure." This is ironic because it is his treasure, namely "a pipe of ... Amontillado" which he supposedly keeps in his vaults, that he uses to lure Fortunato into his trap. One might also infer that Montresor's treasure is his reputation, which he believes Fortunato has somehow injured. It is this perceived injury which motivates Montresor to get his revenge against Fortunato.

Montresor describes his family's coat of arms as, "A huge human foot d'or, in a field azure; the foot crushes a serpent rampant whose fangs are imbedded in the heel." He clearly sees himself as the golden foot in this image, crushing Fortunato, who is represented by the serpent. The implication is that Montresor believes that he is the hero and Fortunato the villain. He believes that the crime he is about to commit is justified, because Fortunato, like the snake in the coat of arms, has tried to injure him. Furthermore, he believes that the crime he is about to commit is necessary, as Fortunato's "fangs" are "imbedded" and thus need to be removed.

Montresor's family motto is "Nemo me impune lacessit," which translates as, "Nobody harms me with impunity." This suggests that Montresor is a very proud, vengeful man. For every perceived injustice done to him, he feels that he must respond in kind. This motto, in combination with the family crest, is the justification he uses for the cruel crime he commits against Fortunato.