Describe the Montresor family arms. What significance do they have in the story?

In Edgar
Allen Poes short story , Montresors coat of arms and family motto accurately reflect his
violent character and foreshadow his cruel actions. The coat of arms is described by Montresor
as,

A huge human foot dor, in a field azure; the foot
crushes a serpent rampant whose fangs are imbedded in the heel.

This image of a giant golden foot crushing a serpent that has bitten the heel is
interesting because it indicates that the Montresor family is violent and will crush those who
oppose or offend them. Montresor also reminds his guest of the Montresor family motto,
Nemo me impune lacessit. The rough translation of this Latin phrase is,
no one attacks me with impunity. Based on the family crest, it is unwise to cross the
Montresor family!

To fully understand the significance of this symbolism and
the narrators cruelty, it is important to revisit Montresors rationale for murdering Fortunato.
In the opening lines of the story, the narrator reveals,

The thousand injuries of Fortunato I had borne as I best could; but when he ventured
upon insult, I vowed revenge.

The implication is that
Fortunato has repeatedly insulted the Montresor family in some unspecified manner. When
Montresor cruelly buries Fortunato alive in the vaults of the family home, his actions mirror
his coat of arms and adhere to the family-values of the crest.

I hope this
helps!