"I didn't think I was going to do it actually," the 43-year-old actress told AP Radio News in a recent interview. "But then, they were there and the snake was there, and I didn't want the snake to win, so I put the snake on.
"And actually, I grew to really love the snake -- by the end of the day."
Parker is shown with the snake over her shoulder and down her back. In one Showtime ad, David Duchovny, who stars in the new series "Californication," is shown with the snake coming over his back, its head on his bare shoulder. He's tossing an apple, with a big bite taken out of it, into the air.
"I've been naked quite a bit, actually," Parker said of posing for the photo. "You Google me, you'll see it all."
The third season of "Weeds," which also stars Kevin Nealon, Elizabeth Perkins and newcomer Matthew Modine, was to premiere Monday night, followed by the series premiere of "Californication."
Parker stars as a widowed suburban mother who starts selling marijuana to support her family in "Weeds."
The actress won an Emmy Award for "Angels in America." She's won two Golden Globe Awards, one for "Angels in America," the other for "Weeds," and had a recurring role on NBC's "The West Wing." Her screen credits include "Fried Green Tomatoes," "Boys on the Side" and "The Client."