Is this the grossest birthday cake ever?

The cake showed an image of a cow giving birth to a calf. Photo / Facebook

A mum has surprised her farmyard-mad son with a birthday cake that depicts a cow giving birth.

Jamie Packard, from Saskatchewan, Canada, was taken aback by four-year-old Benz's unusual request but was determined to whip up the animal-themed treat.

Taking to Facebook, Jamie said: "For the last couple of months, Benz has been asking for a 'cow having a calf' cake for his birthday."

He rejected all other suggestions, so they decided... well... a cow giving birth would have to be done.

"As I'm moulding rice crispy squares into little hooves I'm thinking to myself, no Mother is ever really prepared for this kind of stuff," she continues.

"And as I'm applying cherry pie filling as afterbirth, I found myself thinking.. Thank goodness it's only family coming to this party!"

Here's the finished product. It's... as graphic as it sounds.

The finished product. Photo / Facebook

But we're sure it was delicious.