Lyssa is the goddess, or the personification, of anger and insanity. Also associated with rabies and crazed frenzies. She is shown wearing a short skirt and crowned with a dog-head cap to signify rabies.
Parents
She is a child of Nyx (Night) and was born from the blood of Ouranos (sky) when half of his body was thrown into Tartarus when Kronos cut him up. Some myths say that she is the child of Gaea (earth) and Aither (light).
Myth 1
Hera never liked Heracles, the son of her husband. One day, she sent Iris to tell Lyssa that she needed a favor. When Lyssa arrived, Hera told her that she wanted her to send Heracles mad. At first she refused, for Lyss didn't want to anger Zeus. But finally she gave in. She went to the home of Heracles and drove him mad. In his fit of madness, Heracles murdered his wife and children. Lyssa ended up lifting his madness, but that damage was done.
Myth 2
When the hunter Actaeon spied on Artemis bathing, she turned him into a stag for what he did. Artemis asked Lyssa to make his hunting dogs mad so they would kill Actaeon. She agreed and sent the dogs into a mad frenzy. They hunting dog teared him apart and killed him.