Last year, during the height of Frozen mania, when every little girl (and maybe not so little girl) in your extended family was all "Elsa this" and "Ana that", a YouTube user by the name of SydneyAmber S took the song "Do You Want to Build a Snowman" from the film and give it a little Arkham Asylum twist with a frozen Harley Quinn.
Instead of little Ana singing to her big sister Elsa, it's now Harley trying to get her "puddin", a.k.a. The Joker, out of his doldrums behind bars by asking him to break out and have some fun killing that pesky Batman (or possibly rob a jewelry store instead). Throw in some cute references to Harley's relationship with her other criminal BFF Posion Ivy, and SydneyAmber made a Disney-style love letter to the classic Batman: The Animated Series.
Now another YouTube user named Michael Smith has taken the song and given part of it the CGI animated treatment. So far he's only animated one verse from the song, but he's definitely animated it in the classic style: this is the original Bruce Timm version of Harley Quinn all the way, not the modern "Suicide Girls" version, or the even more recent "Roller Derby" version made popular by artist Amanda Conner (soon to be seen in live-action form by actress Margot Robbie in Suicide Squad). He's included an animation progression breakdown as part of the video, but if you stay till the very end, he's added a little surprise that's not in the original parody song that's totally worth it.
And just like the original song from Frozen, it's guaranteed this one will stay in your head for the rest of the day.