If I’m not mistaken, they’ve taken the voice track from an originally-hand-animated Looney Tunes and remade the entire imagery in CGI. A YouTube user then converted it to SBS (side-by-side) 3D video.
On the desktop, YouTube will display this only in anaglyph. So I used my poor-ass VR glasses to see it. It worked remarkably well! It had great depth in some scenes. Even in the opening logo:
See the video after the break.
As usual, YouTube confuses the hell out of everyone by showing an SBS 3D Preview, not the anaglyph desktop users get stuck with.