It took six to eight weeks for the tattoo to be completed.
Prue enlisted the help of tattoo artist Tony Gibert from Juicy Quill Tattoo in Alberta.
"I think it's amazing to be able to comfort your son like that," the tattoo artist said.
"It's more than just your kid seeing your name, or something, you get to actually, like, really change the way he feels about himself."
Gibert said the tattoo was "pretty painful".
"He's been through the wringer sitting for that," he added.
The dad has admitted he didn't know the process would be so long and painful.
Still, he says, "it felt good to do it".
"I'm kind of glad I didn't know how long it was going to take," he added.
The dad is happy with the result and does not regret the pain he put himself through to help his son feel better about his birthmark.
"Now we have the same marks for life."