GIANT ruckman Shane Mumford may be one of the most feared figures in the game but he revealed his softer side on Instagram following the birth of his baby boy.

Mumford's wife, Eva, gave birth to the couple's first child, Oliver Charles Mumford, in the small hours of Thursday morning - 1.29am AEDT to be exact.

Visibly proud, Mumford announced Oliver's arrival on Instagram on Thursday afternoon with a very cute photo and hashtags #futurefatherson and #mumsatrooper.

Baby Mumford weighed in at 4.09kg, just 103kg shy of his father. 

GWS said on its website: "Little Oliver could become the Giants' first ever father/son draftee … In around 18 years or so, contingent on his dad playing another 49 games in the orange and charcoal."

It's been a big off-season for Shane and Eva who tied the knot in a low-key ceremony just a few weeks before Oliver's arrival.

Mumford has a few weeks off to spend with his new family before returning to training with the older players on December 5.