Fans of Buffy the Vampire Slayer remember Michelle Trachtenberg as Sarah Michelle Gellar's whiny kid sister, Dawn Summers. That's why, for those who've seen Eurotrip — which ain't many, since it kinda tanked last weekend — her role may come as quite a stunner. You see, the petite 18-year-old actress is sick of her wholesome "Dawny" label. So she's thrilled to show off her acting range, not to mention her taut figure in a itsy, bitsy bikini.

"I basically wanted a project that showcased the fact that I was 18," Trachtenberg tells TV Guide Online. "I wanted a role that was age appropriate, [so] people would realize that I'm not the annoying little sister. I never was, really, but they made me be annoying, darn it!"

Though the TV girlie-girl hoped to graduate into womanhood on the big screen, she had her limits. "Right now, I'm going to show off my body until I can't — like when I'm 60 or whatever," she sasses. "My character did originally have a flashing scene, but I wasn't going topless. I sat down with the directors and said, 'I love the script. I think it is really funny, but if I'm going to be a part of it, I will never show my boobs.' If, creatively, it is necessary to do something like that, then I am all about that. But I'm not about the gratuitous t---."

Look for Trachtenberg to don more daring outfits in June, when Six Feet Under returns to HBO. The thesp will do four episodes of the funeral drama as a pop singer called Celeste. "Honestly, when I wrapped Buffy, I made a mental note that I did not ever really want to go back to TV," she says with a sigh. "But Six Feet Under just kind of popped out of nowhere. I was like, 'I love the show. I have to. It is the coolest thing!' [My story line] is a complete spoof, and not what Six Feet Under normally has. I'm really happy to be the girl that they wanted to spoof it up with.

"[Celeste] is sort of a combination of everyone," she previews. "Christina Aguilera, Britney Spears, Pink and Jennifer Lopez. It is so much fun."

Hmmm... Why is she showing off her pipes now? Don't forget she was very vocal about refusing to serenade viewers in Buffy's famous musical episode. "I wasn't proud of my singing abilities," she recalls, adding, "I shouldn't have to be forced to sing, but apparently, I can carry a tune, so I'll go with that."