Jennifer Aniston is feeling wackier than ever in the New Year! Appearing on Jimmy Kimmel Live on Tuesday Jan. 8 -- the ABC show's first episode in its new, earlier time slot of 11:35 -- the 43-year-old We're the Millers star entered with a bang . . . many bangs!

Wielding a sledgehammer and protective goggles, Aniston, clad in a tight black dress, destroyed Jimmy Kimmel's brand-new desk as a way to ring in the new year and Kimmel's new start time. After that extended bit, Aniston and Kimmel dished on their holiday trip together in Cabo San Lucas, Mexico, where Kimmel, 45, bonded with Aniston's fiance Justin Theroux plus John Krasinski.

Aniston revealed that Kimmel is an "amazing cook" and whipped up an Italian meal for New Year's Day. Her contribution to the feast? A "trailer-trashy ham and cream cheese" number. Kimmel, Theroux, 41, and Krasinski, 33, joined the ladies -- Aniston, Kimmel's fiancee Molly McNearney, and Krasinski's wife Emily Blunt -- for a spa day.

Even furnishing photos from the day of his-and-her pampering, Aniston added: "All of you boys were secure enough in your masculinity to join the women on spa day. So the girls had massages, whilst the men were having manicures and pedicures."

Capping off the freewheeling chat, Aniston then took a pair of scissors to give Kimmel a haircut on live TV. "I'm so nervous, I'm kind of shaking, I hope that's OK with you!"

Watch a clip from Aniston's appearance now!