Cool girl who is genuinely awesome most of the time. Until she starts making up crazy lies. A "savanah" will regularly tell you about events in which she gets out of receiving speeding tickets because of showing cleavage (she doesn't even drive), stealing her neighbor's purse for her mother's birthday present while dodging attack dogs, or being brutalized with her 10 year-old sister in mosh pits.
Her lies eventually become so ridiculous that you end up having to write about her on Urban Dictionary.
Man 1: "Holy shit. I got raped by a doberman at a Lady GaGa concert last weekend."