McDonald Brazil's new Kopenhagen Cat's Tongue Duo McFlurry features chocolate truffles with a white chocolate filling (hence the "Duo"), mixed with vanilla soft serve and a choice of either hot fudge, strawberry, or caramel syrup. Apparently, there's an option to add even more truffles to your McFlurry.
In case you're wondering what Cat's Tongue chocolates normally look like, I've included a picture below:
First Photo via McDonald's Brazil. Second Photo via Kopenhagen.