A vixen is a female fox. Or it can be a woman with a temper. If you really want to insult a woman who is a little short on patience, call her a vixen. She won’t like it.
Somewhere along the line the word vixen came to mean a hot-headed or ill-tempered person. Nowadays vixen is often used as a derisive term for an unpleasant or mean woman. Vixen also gets used frequently in descriptions of female film characters. In this way it doesn’t really mean that the character is bad tempered. As slang, to call someone a vixen means that she's sexy and flirtatious, a label she may or may not like.