Vixy McCloud (née Reinard) was the mother of Fox McCloud and the wife of James McCloud.
Very little is known about her, as her only appearance was in the 1993 Nintendo Power Star Fox comic. She was described as being very beautiful and caring, and attracted the attentions of Andross, who became infatuated with her. Unfortunately, she was already in love with and married to James, and had a son. As it was, Andross planned to get rid of them by installing a bomb in James's car. Unfortunately that day, Vixy's car was broken down and James let her drive his in order to get to work, oblivious to Andross' actions. The moment she started the car, she was killed in the following explosion, leaving both James and Andross stricken with grief.
Her appearance is only seen in a photograph that Fox keeps of her; however, Fara Phoenix was noted for having an uncanny similarity to her. This may imply that, although she is clearly a Red Fox in the photo, she may have been part Fennec.
Despite the Nintendo Power comic largely being incompatible for the current games - the reason for this was that it was based on the first (now non-canon) Star Fox game - Vixy (at least as a character) is one aspect from the comic that can easily fit in with the current timeline.
Vixy's death means that Andross was supposedly responsible for the demise of both of Fox's parents, with different motivations; Vixy's death was unintentional, whereas Andross clearly had a hatred for James.
Vixy's first name comes from "Vixen", which is a term for a female Fox.
Her last name comes from the "Reynard Cycle", a medieval French book about the adventures of a clever fox named Reynard (fr: Renart). The book was so popular in the Middle Ages that it gave its name to the animal (French for fox is renard, formerly goupil.)
With this in mind, it may provide a slight explanation for Fox's first name.