You can't see it at first sight because the grass animation is only slight. What you see here is an animated autotilemap!
I restructured and cleaned up my blend file and took the program Spritesetter for it. So I have less time for modeling. Out of 5 tiles I get 47 with Tilesetter.
So I can focus on the essential and don't have to edit all 47 tiles by hand. I wish I had known it earlier.
Because now not only one camera jumps from tile to tile, but every tile has its own camera, animation has become possible.
Animated tilemaps will bring a lot of life to the game world, which I am really looking forward to.

The water autotilemap is already in progress:

Unfortunately the video is in German language, but it also gives some insight.