Portrayed in the early era as a tall, ugly, somewhat crazy individual, she had a huge infatuation with Jughead Jones, usually resorting to devious means to get Jughead in her clutches.
In the later era, she's been portrayed as an average, somewhat likeable individual, who's infatuation for Jughead has lessened quite a bit. She now has other interests that keep her mind from Jughead, including Archie Andrews, to keep her company. Jughead actually seems a bit jealous in fact......