I’m guessing this is someone’s video of an old MOTU commercial that was being shown by Mattel at SDCC this year (for instance, note the swelling Star Wars music in the background). According to one of the commenters on Youtube, this video was actually made by Filmation to help sell the series to TV, but it’s clearly not in the same style as the actual Filmation cartoon was.

Lots of extra detail, real facial expressions, an Alfredo Alcala-looking Skeletor–am I alone in wishing the original series had looked more like this?