Magni’s hero power has the hammer animation occurring twice since the last patch. At least on PC, haven’t tried playing mobile since the patch.
Was Baku the Mooneater or Genn Greymane or some other card also in-game?
May be related to: April 4th Update Bug
No, no Baku or Genn.
Noticed the same issue a few minutes ago, but I see other people reported it already. Made a short video with my phone (too lazy to install video capture software just for this 
):
https://www.youtube.com/watch?v=lteITviv0FY