He writes that Rikki-tikki feels pride and responsibility.
Fitzgerald wants to portray and characterize the US society in the 30s. By making this question about race and their opinion about it, the author intends to characterize American society as competitive, a value that is repeated throughout the story. One of the main purpose of the novel, in fact, is to show how competitive, materialistic, and full of glamour the society is, especially the people who live in East Egg like Tom and Daisy.
Throughout this passage, Wiglaf is presented as a model of loyalty. When all other warriors act like cowards, retreating to safety, Wiglaf decides to risk his life and stand by his old king in this last battle. He still doesn't act as Beowulf's equal, but he nevertheless offers him support, as his sworn warrior. Beowulf is indeed encouraged by this act and manages to kill the dragon while receiving a mortal wound himself.
It signifies a story that began sadly but ended happily