The reality star posted a hilarious video on Instagram Sunday, showing her four children's own elves in glass jars -- where she says they'll remain until at least the 23rd so they can quarantine ... this because she just needs a break from all the EOAS household fun.

It's freaking funny ... Kim wrote up a note for her little ones -- North, Saint, Chicago and Psalm -- which makes it seem like it's from the elves themselves. It says, "We are on a 10 Day Quarantine! We still have our magic and will be back to flying around in 10 days."

Sounds like this will do the trick and give Kim and co. some peace of mind -- she says she's tired of having to remember to collect all 4 of these things from all over the house, so she took things into her own hands and deemed them to be riddled with COVID. Don't worry, kiddies ... something tells us they'll make a full recovery -- even if it's less than 14 days.

If you're unfamiliar, Elf on a Shelf is a popular holiday tradition. It's based on a book of the same name and entails you putting your own elf in secretive places throughout your home to "spy" on people for Santa, to make sure they're nice throughout December.

There's been a new twist to the meme/game, and celebs have gone to town on it this Christmas season. Instead of an elf, they're putting other celebs and/or movies and characters that rhyme with their own name, and photoshopping them onto their shoulders.

For example ... Elizabeth Banks plopped Tom Hanks as Forrest Gump onto her shoulder, and dubbed it Hanks-on-Banks. Reese Witherspoon got in on the fun too, and did "Grease"-on-Reese. Ryan Seacrest did Luke Bryan-on-a-Ryan, and Mariah Carey did Jim Carrey-on-Carey ... and J Lo's actually had a few ideas that she loved. She compiled her favorites in a post.