The central animals in "Rikki-Tikki-Tavi" certainly adopt many human characteristics, including: human emotions, thought, dialogue, and actions. Kipling's use of this literary device, known as anthropomorphism, results in Rikki-Tikki-Tavi reading like a fable.
The hero of the story, the mongoose Rikki-Tikki-Tavi is brave and loyal, willing to defend his little boy despite great personal risk to himself. The villainous cobras are sly and cunning, merciless in their scheme to rid the house of its human inhabitants. Other characters like the tailor bird, Darzee, have personalities that reflect attributes of their animal form. Darzee the tailor bird just so happens to be flighty and bird-brained; his impulsive personality earns him a scolding from Rikki.
Kipling connects the animals' personalities to their animal form to deepen their characterization.