Hatchimals aren't hatching and parents aren't happy.

It was the must-have toy of 2016, the one children all around the world scribbled on their letters to Santa this Christmas. Hatchimals.

But for those lucky enough to find one in their stocking, it may not seem all it was cracked up to be (see what we did there?).

For the uninitiated, a Hatchimal begins an an egg that opens after 30 minutes of continual play to reveal an interactive, fluffy Furby-like toy. The little critter eventually grows through three life stages – from baby to toddler to child – and can be taught to walk, talk, dance, sing and play tag along the way.

Great in theory. However, the company behind the juggernaut, Spin Master, is being bombarded with complaints on social media from hundreds of angry parents claiming their children’s Hatchimal hasn’t, well, hatched.

"Good old spin master dropped the egg on this one. Ur product is junk junk. Ours didn't hatch either and spin master was contacted and did nothing about it [sic]," wrote one Facebook commenter.

"I am so upset," wrote another. "My little girl got her Hatchimal this morning. After well over an hour, I had to break the egg open to get it out. That ruins the excitement of the toy."

Spin Master posted this to their Facebook page on Boxing Day in response:

But over the last couple of days, the complaints have just kept coming. There are over 1.7K comments on Spin Masters post, and currently the 'angry' reactions emoji is in the lead.

"I've got a devastated 5 year old because her Hatchimal is an ABSOLUTE DUD!!! How do you explain that santa delivered a dud??? Terrible company... terrible toys,” wrote one commenter.

Among the grievances are several relating to how Spin Master's customer service team has been handling the complaints, including: "After being on hold for 2 hours 57 minutes, get through to an agent who tells me I need to speak to someone else and then get cut off....."

Spin Master wrote that it has placed additional staff on its Consumer Care team to handle this busy period and is working continuously to respond to customers.

While we don't envy the parents who forked out $70 (or potentially hundreds via eBay after they sold out in most retailers) having to deal with a disappointed children, we don't envy the people on the other of the phones either.

Stay strong, everyone.

Mamamia has contacted Spin Master for comment.