Here's one surefire way to ensure that Charmed's young male fans follow the WB drama to its new home on Sunday nights this fall: Dress up series star Alyssa Milano as a sexy mermaid, as producers did for the show's two-hour season premiere Sept. 22 (8-10 pm/ET).

"I have on pasties and a fin," Milano tells TV Guide Online, laughing. "I went for a wardrobe fitting and I was like, 'Where's the seashell top?' They were like, 'It doesn't look good, so we're just going to add scales and paint them on your boobies.'"

Not that it makes much difference, but why exactly will Milano's bewitching alter ego, Phoebe, be pulling a Daryl Hannah on viewers? "Why does anything ever happen on Charmed?" she muses, adding, "It's in order to find a sea hag.... obviously."

No, that's not a subtle dig at former co-star/nemesis Shannen Doherty. But this may be: Milano says that she and Holly Marie Combs have gelled "perfectly" with new sis Rose McGowan. "We're having a great time. She's a great energy to have around."

Even the WB's decision to banish the cult fave to Sundays — historically the WB's worst night ratings-wise — hasn't dampened the trio's spirits. "Actually, I think its going to be good for us," Milano says of the move. "Sunday night is having a bit of a rebirth with The Practice, Six Feet Under and Alias. It's becoming a good night for television."