They say the apple doesn't fall far from the tree.
But as these unusual Face Swap photos prove, often family resemblance doesn't quite run in the, um, family.
In a Facebook post started by the New Zealand-based parenting expert, How To Dad, hundreds of fathers have taken to the social networking site to share their Face Swapped selfies with their babies.
The results are hilarious, bizarre and sometimes a little disturbing.
"I think there's time for one more Baby Face Swap marathon before Christmas... post yours below," How To Dad wrote above his Facebook post.
"This.Will.Be.Good.," he concluded.
Since the New Zealand-based blogger uploaded the message on Christmas Eve with his own picture, nearly 7,000 people have liked the post.
It also has close to 600 comments - and accompanying photos.
One picture that has amassed 1,000 likes already is a FaceSwap of one man and baby.
The photo has even attracted the attention of How To Dad himself, who jokingly commented underneath: 'This has ruined Christmas'.
Other snaps show women posting pictures of their husbands and writing things like: "Cracks me up every time I look at it. Hubby and baby".
Another woman wrote: "My husband swapped faces with our baby and ended up looking like the kid with the lisp from Stranger Things".
The thread continued with popularity throughout Christmas Eve and Christmas Day.
Meanwhile, How To Dad also kept providing his commentary on many of the photos.
Festive Face Swap, anyone?
Enjoy more hilarious face swaps from the thread below.