Ever seen a baby dressed as Frida Kahlo? Thanks to Neil Patrick Harris, now you can.

The proud papa appeared on "The Late Show with David Letterman" last night to promote his upcoming Tonys-hosting gig and "Smurfs" movie -- where he showed off some adorable and hilarious photos of his 8-month-old twins, Gideon and Harper.

Apparently NPH and partner David Burtka are making a calendar to "humiliate" and "embarrass" the babies with someday -- and have taken photos of the kids as green beer drinking Leprechauns, Easter bunnies and wearing a unibrow and sombrero for Cinco de Mayo.

Check out the video!