With the release of teaser trailers of "Er Ist Wieder Da" being released about a month ago, at least two parodies have already been made despite the movie not even being released yet! Hopefully more parodies will be made after the movie has been released in a month.
Links to the parodies here and here. As far as I know, Subtitlecomedy made the first ever parody of Er Ist Wieder Da, about 3-4 hours before mine.