The little guy brought some Christmas spirit to the holiday in the cutest way ever.
Already getting into the Christmas spirit! Carrie Underwood celebrated the final show of her Cry Pretty 360 Tour on Thursday night, and she refused to let Halloween go un-celebrated.
"Going into the Meet and Greet, but tonight we're calling it the Scream and Greet!" she told her fans on Instagram Stories.
She later posted a family shot at the event of herself, her husband, Mike Fisher, and their two sons, Isaiah, 4, and Jacob, 9 months. The entire family got into the costume spirit, rocking their own tricked-out looks.
"Hope everyone had a good #Halloween ! Lots of love from Cheer Bear, The Grinch, Max and Buck Daniels..." Underwood captioned the group shot.
Though the country singer has on a cute Care Bears costume, her oldest son, Isaiah, has clearly won the family contest in his head-to-toe the Grinch Who Stole Christmas look.
Little Isaiah is rocking a pair of thick, hairy green "legs" along with a fitted Santa outfit, green face paint, and green hair. Turns out his mom got in on the fun, painting his makeup on herself, which she documented on her Instagram Story.
Isaiah got his little brother in on the fun, having him dress up as the Grinch's loyal dog, Max.
Underwood has opened up in the past about her eldest's big personality.
"Isaiah, somebody recently called him the Mayor of Catering, because he's like, 'Hi, everybody!' And loves seeing everyone," she recently told Stephen Colbert of having her kids on tour with her. "He's got his little scooter he rides around the venues in. He's such a people guy, so he's living the dream."
ET recently spoke with Underwood about tour life. Watch the clip below for more: