Tara was transformed into a vampire on the HBO drama, after being shot in the fourth season finale.
"I was initially terrified because I was being shot in the head," the actress told TVLine. "But I was also excited because I was going to be able to create a whole new Tara in a way, and explore a whole new physicality."
Wesley also revealed that she was having "fun being feral" in the latest True Blood episodes.
"She's only been a vampire for a minute, and what transpires when she comes out of the grave is the most chaotic crazy thing," she explained.
"And the most important thing is the relationship between her and Sookie (Anna Paquin) and her and Lafayette (Nelsan Ellis) and how all of that plays out."
The 33-year-old added that Tara's new condition will be "a game-changer on many levels".
"Only time will tell [how it plays out]," she said. "I can say that the relationships will never be the same."
The fifth season of True Blood continues on Sundays at 9/8c on HBO. It will air on FX in the UK later this year.
> 'True Blood' will return for sixth season, says star Todd Lowe