ICYMI: The 17 Best Celebrity Halloween Beauty Costumes of 2015

Thanks to makeup artist Alex Faction, J Lo looked like the sexiest haute couture skeleton we've ever seen. Check out that stunning negative-space contouring!

A white-blond wig with crown braids and glittery eyelids transformed Kylie into a chic eskimo. And if you want the makeup product details, head to Hrush Achemyan's> Instagram.

No, you're not looking at a poster for Grease — that's actually Gigi made over to look like Sandy. Makeup artist Erin Parsons created the model's sexy red lip and eyebrow-grazing eyelashes.

Head to Heidi's Instagram to see quick videos showcasing how she morphed into Jessica Rabbit for her annual Halloween party in NYC. Faux eyelids and lips were part of the special-effects makeup done by Mike Marino.

If looking like a devil involves bombshell waves, an ombré red lip, and smoldering smudged black eyeliner, then we will definitely copy Alessandra's style for our next Saturday night out. Makeup pro Beau Nelson can be credited for this mesmerizing face paint, and Gio Campora took care of that voluminous hair.

Perhaps Gwen's cohost on the The Voice, Blake Shelton, inspired her haunted cowgirl look.

Related: Gwen Stefani Talks About Her New Urban Decay Collaboration

To emulate Marge Simpson, Emily painted her entire face and body yellow and topped her head with a fluffy blue beehive wig.

Fergie wins the award for cheekiest fashion-girl costume, dressing as Karl Lagerfeld's famous cat, Choupette. Ronit Shapow is the makeup artist responsible for her kitty-cute makeup, while Jayson Medina styled that adorable white bob wig. (PS: Her husband, Josh Duhamel, is outfitted as Karl.)

Ariana paired her signature cat eye and half-up ponytail with a vampy lip and stitched lip for a subtle yet creepy look.

The late Aaliyah's memory lives on thanks to Keke, who dressed as the music icon from her "Try Again" video. Sleek, shiny hair and shimmery eye makeup looked gorgeous on Keke's skin.

We know Katy loves to transform into characters for the stage, and this Halloween she held up her reputation by morphing into what she dubbed "the sad girl's club." Those epic, cool cartoon eyes were done by makeup artist Michael Anthony.

Taraji's leopard-print eyelids, winged lip liner, and teased hair made her feline costume a standout. You can thank Ashunta Sheriff for the fierce face paint.

It looks like Shay loved her Poison Ivy makeup so much that she posed with her artist, Patrick Ta, to show off those come-hither eyes.

Behati and her hubby, Adam Levine, look unrecognizable dressed as Rainbow Brite and a dapper skeleton.

The actress and beauty entrepreneur sure does look like one pretty kitty. And yes, you can easily master this at home; all you need is a black liquid eyeliner wand and some pink lipstick.

Sophia played the part of Mia Wallace from Pulp Fiction perfectly.

The fashion designer signed her Instagram "Mr. Jack Skellington." This is another face paint look you can definitely try at home with just two colors: black and white.