The best and weirdest celebrity Halloween costumes

For most of us, Halloween is a fun excuse for a party — but for lots of celebrities, it's the night they go to amazing lengths to impress the world with their costumes.

Here are some of 2015's best and weirdest efforts...

Neil Patrick Harris and family as the Star Wars clan

In a galaxy far far away, the How I Met Your Mother star dressed up as Obi Wan Kenobi while his family donned Luke Skywalker, Princess Leia and Han Solo costumes...

Michelle Gomez as Minnie Mouse?

Or should we say MISSY Mouse...?

Arthur Darvill as Kurt Cobain

The former Doctor Who star rocked out as the Nirvana frontman.

Hugh Jackman as Mario

The actor looked extremely happy to be in this video game-inspired outfit. It looks nice and warm, too...

Tyra Banks as Richard Branson

Yes, you heard that right. The model and TV presenter dressed up as the Virgin mogul. And it's brilliant.

Hugh Grant as some sort of lion...

We'll just leave this here for you to stare at in strange wonderment...

Jimmy Kimmel as Princess Leia

Those side buns actually suit the chat show host remarkably well...

Allison Williams as Belle

The Girls actress, who plays Marnie, went as Disney's Belle from Beauty and the Beast. She's paid such close attention to detail that she almost looks like the animation...

Jessica Alba and Kelly Sawyer as Romy and Michelle

The actress and her model friend went all 90s as the hell-raising duo in Lisa Kudrow and Mira Sorvino's 1997 movie.

Made in Chelsea's Jamie Laing and Alex Mytton

Looking smooth, 'bois'...

Channing Tatum as The Cat in the Hat

The Magic Mike actor went as the tall, well-dressed and mysterious feline from Dr Seuss's iconic book...

Ellen DeGeneres as Karla Kardashian

The TV host transformed herself startlingly well into a long-lost (and fictional) member of the Kardashian family...