What does the mongoose represent?

When the mongoose first appears in The Brief Wondrous Life of Oscar Wao, Diaz includes a footnote that says "the Mongoose has proven itself to be an enemy of kingly chariots, chains, and hierarchies. Believed to be an ally of Man. Many Watchers suspect that the Mongoose arrived to our world from another, but to date no evidence of such a migration has been unearthed" (Diaz, 151). There are many possible "kingly chariots, chains, and hierarchies" in the lives of the characters in the book, and the mongoose seems to represent some sort of supernatural protection, encouragement, or guidance against these forces.
The mongoose first appears to Beli as she lies in the sugar cane field after being brutally beaten by some men who are employed by Trujillo. Trujillo was the dictator who ruled over the Dominican Republic while Beli was living there. The mongoose fights some "chains and hierarchies" here because the mongoose is helping Beli survive after the orders of this dictator. The mongoose encourages her to get up and to find help so that she will not die in the field (Diaz, 149).
The mongoose appears to Oscar later in the book when he attempts to commit suicide by jumping off a bridge. The narrator describes how Oscar should have died from that fall, but he got extremely lucky and landed on a concrete barrier that had some plants and shrubs growing on it. Instead of dying, Oscar escapes with two broken legs and an injured shoulder. The mongoose appeared to him right before he jumped and it seems to have saved his life here, just like it saved Beli's years ago (Diaz, 190-191).