User blog comment:Gourgeist/Who Is The Beast Titan?/@comment-25472766-20141005053628

The only person that could be vaguely the Beast titan is marcel, but we don't know anything about him. It is impossible for it to be Grisha or Kenny, without it being a plothole. My guess is either he is a intellignet Titan or He's a Titan shifter that hasn't been in contact with these humans for more than 70 years.