Shave.
Yeah, from full beard to naked face. My wife may never forgive me.
My son is okayish now, my boss at work is happy, the mom unit misses scruffy me.
Oh well.
He really freaked out at first. I hadda go to my knees hugging before he’d look at me. Didn’t think about that, I should have warned him.
Did you tell him, ‘Next time I shave, the skin comes off!’ ?
Did that years ago and the dog was thrown for a loop. I guess I sounded right but looked like lunch. 
My brother shaved and then went to pick up his then-three-year-old from Vacation Bible School. She refused to have anything to do with him until he had talked to her for a bit. He had to talk all the way home so she could keep hearing his voice and know it was Daddy.
Your son is the perfect age for someone to set him up with this, in case he wants to get back at you.
When my uncle went from a full beard to just a mustache sometime back in the early eighties, it absolutely shocked his youngest daughter, who at 21, had never seen her dad with anything but a furry face. One of his toddler grandsons actually screamed and cried for quite some time.
Moral of the story: if you suddenly decide to radically change your facial hair status after a few years, give the kids in your life a heads up. 
Next time, just shave one half of your face first to get him acclimatised.
I am a twin. When we were three (I don’t remember this) my Dad decided to shave off his full beard. He was worried about freaking us out, so he sat down in front of us to first cut his beard and then shave. Apparently we both watched in fascination, THEN cried when he smiled at us, job complete!
I did the same. but with only my moustache. I shaved it off, my daughter (who was about three at the time) took one look, burst into tears and said, “Daddy, put it back!” I’ve kept it ever since.
Regards,
Shodan
My little girl did this too when my Mig shaved his head and mustache. She was only around four at the time, but he had to wear a cap for a few days otherwise she wouldn’t go near him. We thought it was because of her sensory issues. Looks like it’s pretty normal!
Years ago I shaved off my beard but kept my moustache. A girl at work looked at me oddly, and asked if I’d grown a moustache over the weekend.
I shaved my moustache and goatee off once. My son took one look at me and said, “You look like shit. Grow it back.”
Friggin’ teenagers.
Lest the women feel left out, let me assure them that we have the same power to induce panic in our children, only it requires hair dye.
Blonde Mama freaked the little one out right quick, I’m telling ya.
I had a full beard for 20 years, then shaved it off, leaving just a moustache. It’s amazing how many people thought I had just grown a moustache.
When my sister made a radical change in hairstyle, her then preschool son looked at her and said tearfully, “Are you still my Mommy?”
When I shaved off my beard my church’s secretary ( I’d been attending for over 5 years) asked me if I was visiting with a member or just trying the church.
That’s supposed to be scary? Pfft. Where are the evil clowns?
This is exactly what I did with my two boys, when I shaved my beard, for the first time since college, many years ago. I vaguely recall that one of them wasn’t happy with it (the youngest, I think, who has always been extremely change-resistant); but neither of them failed to recognize me afterward, which I think was the point.
My Dad shaved his beard off when I was young. My Mom (they were divorced) dropped me off at his house one afternoon, I went and rang the doorbell and some strange man answered the door. I asked nervously if my Dad was home. It took 15 minutes to convince me it was him!
That goes for dogs, too. In the 80’s, I got a perm, and when I came home my little dogs barked at me furiously and refused to let me near them.
I hated the perm, too, so I completely understood where they were coming from.