Dobrev's character Elena was turned into a vampire in the CW drama's last season finale.
"This season is really intense, for me especially because [now] I am a vampire," the actress told E! Online. "I'm getting to kick some more ass."
The actress - who previously claimed that Elena would "freak out" following her transformation - added that the character is "becoming a tough cookie" in the new episodes.
"Before she used to talk about being independent, and now she has a chance to be," Dobrev explained.
The Vampire Diaries recently cast 90210 actor Blake Hood and Southland's Alyssa Diaz as new followers of the evil Klaus (Joseph Morgan).
The series returns to The CW in the US for its fourth season on Thursday, October 11 at 8/7c. In the UK, new episodes are expected to air on ITV2 in late 2012.
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Watch a clip from the Vampire Diaries season four premiere below: