Flying on a passenger jet can be a pretty standard experience from one airline to another.

Unless you happen to book a flight with one of these airlines.

Whether you're a social media junkie, devoutly religious or have a fixation with Japanese cartoon felines, there appears to be an airline willing to cater for even the most unexpected of niches.

Here are some of the strangest and most unique airlines currently jetting across our skies.

This South African budget airline is known for its wicked sense of humour - not to mention its bright green Boeing fleet.

The jets are emblazoned with the near-legendary phrase "Flying 101" and other cheeky labels, such as "this way is up".

On board, its crew is quick with a witty quip and passengers can expect to hear instructions such as, "Please note we do not accept unwanted mother-in-laws or children" and "Please remain in your seats with your seat belts fastened while the captain taxis what's left of our aeroplane to the gate."

In 2011, Kulula famously offered Kate Middleton's family a herd of cows to mark her upcoming wedding to Prince William.

The internet is riddled with other hilarious in-flight stunts and marketing campaigns by the airline.

And while it doesn't take things too seriously in the sky, Kulula is reputed to have a sound safety record.

For Muslim Passengers: Rayani Air

Taking to the skies for the first time late last year, Rayani Air is Malaysia's first sharia-compliant airline.

The airline complies strictly with the tenants of Islamic law: alcohol is banned on flights, only halal-certified food is served and women are required to cover their hair.

Prayers are also recited before each flight takes off.

While it has been popular with many passengers in Muslim-majority Malaysia, Rayani Air landed in controversy last month when it issued dodgy, handwritten boarding passes to passengers, sparking safety concerns.

But it's not the first airline of its kind in the world: sharia-compliant airlines have been operating for some time out of Saudi Arabia and Iran.

Taiwan-based airline EVA Air has taken Hello Kitty fandom to the next level.

A handful of the airline's passenger jets are completely outfitted with Hello Kitty-themed features, and barely a single detail isn't inspired by the beloved cartoon cat.

The Hello Kitty theme extends to toilet paper, headrest covers, utensils and even the food menu, while characters from the Hello Kitty universe are colourfully painted on the plane's exterior.

Last year EVA Air launched its latest addition to the fleet, a Boeing 777 dubbed "Hello Kitty Shining Star", which flies to Houston, Taipei and Singapore.

It's not a particularly cheap airline, but it has a good safety record and a huge legion of fans.

For Flyers Who Need Mile-High Pampering: Air Malta

This is the airline for anyone who wants to take in-flight comfort to the next level - even if they're relegated to economy, and even on short-haul flights.

Last year, the flag carrier for the Mediterranean island nation introduced in-flight spa treatments, against a soundtrack of soothing music, for all its passengers.

Even though Virgin Atlantic has offered similar spa services, those are reserved for business class travellers.

But on Air Malta, even people in the cheap seats can take advantage of treatments such as neck, back and scalp massages, manicures and hand treatments and even beauty product samples, courtesy of trained therapists on board.

For Those Who Take Social Media Too Far: KLM Royal Dutch Airlines

This airline made headlines in 2011 when it announced passengers could see the Facebook and LinkedIn profiles of other people on board so they could choose who to sit next to.

The idea is to allow people to book seats to optimise the opportunity for some in-flight socialising or business networking.

However, passengers can opt out of having their social media accounts linked with their flight bookings.

Last month, KLM Royal Dutch Airlines entered into a partnership with Facebook that lets passengers manage their flights through the Messenger app.

The app lets KLM customers receive flight updates and confirmation, display boarding passes and hook into a live customer service chat.

For, Um... Swimsuit Fans? VietJet Air

It is hugely controversial, but since 2012 low-cost carrier VietJet Air has staffed its flights with strictly young, attractive, bikini-clad crew.

It's not a standard practice: rather, the bikini-wearing flight attendants are a featured "bonus" on some routes.

Clad in string bikini tops and sarongs in the Vietnamese national colours of red and yellow, the women parade down the plane's aisles for swimsuit shows on those flights.

Despite a backlash, the bikini stunt has proved a cash cow for VietJet, which is now on track to become Vietnam's largest domestic carrier, according to the CAPA Centre for Aviation.

Its chief executive, Nguyen Thi Phuong Thao, also has dreams of global domination.

"We plan to make VietJet a global airline," she told Bloomberg in February.

"We look at Emirates, which came from a country with a small population and has become a global airline. We want to make VietJet the Emirates of Asia."

For Those Who Don't Know Where They're Going: Germanwings

It is a rare passenger who books flight tickets with no destination in mind. But for those that do, Germanwings offers blind booking options with flights as low as AU$50.

Passengers select the city they're departing, and then choose one from a list of destination categories - party, sun and beach, gay-friendly, metropolis, nature, trekking and hiking, culture or shopping.

They can get a sneak peek at some of the cities listed in each theme so they're not totally in the dark. But beyond that, their port of disembarkation is a total surprise.

Metropolis, culture and sun and beach were the most popular categories by blind-bookers, the airline told The Wall Street Journal last year.

Germanwings sold 90,000 blind-booking tickets in 2014, with about 60 percent bought by couples, the newspaper reported.

For Cuddlers: Air New Zealand

For the past few years, Air New Zealand has offered the option of an Economy Skycouch -- dubbed "cuddle class" -- on long-haul flights.

It is essentially a leg rest on economy seats turns into a sofa.

The leg rest folds up horizontally and, when extended in a triple-seat row, forms a flat bed that can fit two adults.

The feature is especially targeted at couples and parents who want to snuggle up with their kids.

But passengers using the Skycouch must wear loop belts that connect with the regular seatbelts so they can snooze in safety.