I just learned that the Countess in Diablo II is based on Elizabeth Bathory, a real-life Countess in Hungary who lived from 1560 to 1614 . She is said to have bathed in the blood of girls in order to preserve her youth. She is often labelled as the most prolific serial killer in history and the female counterpart of Count Dracula. She is also known as the "Blood Countess", "Blood Queen" or "Countess Dracula". She was imprisoned in her own castle, much like her Tower in Diablo 2.
She is the best source of runes in the game. Every time she dies, she is guaranteed to drop at least 1 rune, up to three. Her rune drops depend on the difficulty level of the game:
Normal: El - Ral
Nightmare: El - Io/Ko; above Io (r16) is much rarer.
Hell: El - Ist/Lo; above Ist (r24) is much rarer.
One thing to note though is that the Countess is both Fire and Cold Immune in Hell. That makes it hard to impossible for some builds to farm her efficiently.
Her taunts give more hints to the origin of her character concept :
Your blood will boil
Here for a bloodbath? (laughs)