Rikki-Tikki-Tavi from the story of the same name by Rudyard Kipling, was a mongoose. A mongoose is similar to a weasel with fur like a cat. This mongoose had pink eyes and a pink nose and four legs. When scared or aggravated, Rikki-Tikki-Tavi could fluff out his tail. He is described in the second paragraph of the story:
"He was a mongoose, rather like a little cat in his fur and his tail, but quite like a weasel in his head and his habits. His eyes and the end of his restless nose were pink. He could scratch himself anywhere he pleased with any leg, front or back, that he chose to use. He could fluff up his tail till it looked like a bottle brush, and his war cry as he scuttled through the long grass was; "Rikk-tii-tikki-tikki-tchk!" (Kipling 1)
Rikki-Tikki-Tavi was very curious, and when Teddy and his mother found him and took him back to their house, once he was completely revived, he explored all around him and immediately made friends with the little boy. Rikki-Tikki-Tavi quickly becomes the boy's protector, especially from Nag the snake, who is always up to no good.