The Vellophoi were natives of the planet Vellophon. According to Bernice Summerfield, they looked like feline versions of humans. Benny learned of them that they didn't have a sense of humour and they were genetically modified starting while they were young.
According to Professor Ovmakh, a Vellophoi, they only lived about fifteen or twenty years. They were born conscious and self-aware. Once a Vellophoi chose his vocation, he was genetically modified to best fit that vocation. (PROSE: Mentioning the War)