The Frozen star revealed that her children had recently been bored and dug out a Halloween skeleton which had been packed up.
The youngsters then began pranking their mother by leaving the skeleton in various places around the house, including sitting on the toilet and in the bath.
WATCH: Kristen Bell shares rare video of daughter following hilarious prank
The children even paid attention to the finer details, giving the skeleton some toilet paper when it was on the toilet, and an apple to eat while bathing.
Uploading the hilarious results to Instagram, Kristen joked: "So the kids got bored and dug into the Halloween boxes and now I find Mr Bones around the house just absolutely living his best life."
And in the final post, Kristen shared a rare glimpse of one of her daughters, as the child was briefly caught on camera, before moving out of shot.
In a video, the House of Lies star walked into a bedroom to find the skeleton posing on a yoga mat, while watching a yoga routine.
Kristen's children pranked her with a Halloween skeleton
Fans were full of praise for Kristen's children's ingenuity, with one posting: "Your kids are every parent's goal."
While another added: "Your kids are geniuses. There, we said it." A third agreed, writing: "You have the most creative kids ever. Their minds amaze me LOL."
Many others found humour with the skeleton, with one writing: "At least he's eating healthy and exfoliating his scalp.
Another jested: "I'm jealous of Mr Bones. Man is thriving."
Fans loved how the kids paid attention to the small details
When Dax celebrated his 16th year of sobriety last year, Lincoln and Delta left him an adorable message to celebrate his huge milestone.
Kristen shared the handwritten note on her Instagram, which simply read: "Happy sobriety birthday Dady [sic]."
Explaining the milestone, Kristen wrote: "My daughter woke him up with this sign, and a sketch of the one and only Ronald Weasley (absolutely random and also perfect).
"Happy birthday Daxy. Thank you for dedicating your life to the hard and wonderful work of sobriety, so that we could share it with you. Xo K, L & D."
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