You could changetip to his reddit username.
Yes but his question is more detailed: where he's gonna find a list of possible candidates to pick to gift to?

Not sure if you're being cheeky or not - it doesnt work that way, the person is assigned a secret santa at random. No offense OP, but do yourself a favor and ALSO read into what the person asked for and DO GIVE something that correlates to their wishes at least. Nothing is more offputting than to push 'your hobby' onto me like I always wanted it. In your eyes it's a nice gesture, but if that is the ONLY thing you give them, there is a high chance that the recipient will be like: "Couldn't you just send a giftcard?!?". I gave away paper wallets during a in person white elephant gift giving exchange and it only panned out reasonably because the person who wanted it knew about what bitcoin was and had been interested.
I'm not saying don't give them BTC, I'm saying don't solely give them BTC because that's rather off putting (think of it like this - your secret santa was Bill Gates - you requested a pair of roller skates. He says, "oh, well let me give you something so much better! Here is a $1000 contribution to help adopt cows to a developing village" It does sound great and is likely better than just giving you the roller skates, but you are now feeling resentment against bill gates. Don't be Bill Gates!)
Use a paper wallet and provide instructions that they are to never take pictures of the qr code