Katherine is seen here with Pearl. The latter is played by actress Kelly Hu.
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The Vampire Diaries goes way back in time on the episode "Children of the Damned." Here's a shot of Damon and Katherine.
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Kelly Hu guest stars on the episode "Children of the Damned." She plays a character named Pearl.
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Elena Dobrev pulls double duty on The Vampire Diaries. She's seen here as Katherine.
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The Vampire Diaries Season 1 Episode 13 Quotes

If I see something I haven't seen before, I'll throw a dollar at it.

Damon

I really like this whole menage a team thing. It has a bit of a kink to it.

Damon