We should've asked Terence McKenna...

It could be a subspecies of the "machine elves"...

This was my first thought as well. I've always been fascinated by written accounts of DMT triggering such oddly specific effects for users.

They keep the universe running.

I can answer the what, that parts easy!

The real question is WHY they keep stealing my underwear and left-foot socks?

Making toys, caring for reindeer, sleight maintenance, ...

And spook work for His Jolliness' Secret Service, to keep their Naughty and Nice databases current.