A woman serving as the maid of honor took bridesmaids' dress code to the next level by showing up at her sister's wedding in an inflatable dinosaur costume.

When Deanna Adams told her bridesmaids they could wear "whatever they want" on her wedding day, she probably didn't expect a T-Rex to turn up.

But that's what happened to the American bride, thanks to her cheeky sister, Christina.

Christina explained to the Daily Mail that it all started as a joke after her sister told the bridesmaids to be comfortable in whatever they were going to wear at the wedding.

So, she threw out a couple of off-the-wall ideas, from a dinosaur to a TARDIS from Doctor Who, but it seems the T-Rex was the winner.

The 38-year-old Christina, who hails from Texas, posted a photo of her dino-suit from the ceremony on Facebook. It went viral as it was shared across several social media platforms.

The post was captioned:

"When you're a maid of honor and told you could wear anything you choose... I regret nothing."

Her post garnered over 34,000 shares and 17,000 comments, many remarking that the outfit was hilarious and good fun.

Others praised the bride for having a good sense of humor and tagged their friends to pull the same prank at their weddings.

While speaking to Daily Mail, Christina explained it was 'weird' to see her picture and post go totally viral.

She recalled:

"About a year ago, my big sister texted me, asking if I would be her maid of honor. She, knowing that I'm not a big fan of wearing formal dresses and that I probably wouldn't have a lot of money to buy something really nice, reassured me by letting me know that I could pick out any outfit that I choose."

"I was trying to think of something that I would be willing to wear more than once and thought to myself, 'Well, she did say anything, and if I'm spending more than $50, I want it to be a dinosaur costume, because they're fantastic and I've always wanted one.'"

"I sent her a text so that she could have a laugh - surprisingly, she was ok with it!"

Though other bridesmaids wore dresses at the wedding, Christina went clad in an inflatable T-Rex costume. She added that she eventually gave the costume away as a gift.

The bride commented on the costume saying:

"It's not a joke. It's a giant middle finger at spending thousands of dollars and putting ungodly amounts of pressure on ourselves just to please a bunch of people who, in the end, only want free food and drinks."

"The point was to get married to the man who treats me like I hung the moon, and we did that part."

"My sister is awesome, and I genuinely was not kidding when I said she could wear whatever she wanted."