What I expected to happen was...
Breaking the bottom block in creative or survival of either a double fern or double grass block would just drop a possible seed, not flash the top block as a peony flower.
*What actually happened was...
I broke the bottom block of the double grass or double fern in both creative and survival and the top block flashed as a peony flower before it went away.
Steps to Reproduce:
1. Either be in creative or survival (bug occurs in both).
2. Find a double tall grass block or double tall fern (occurs in both).
3. Break the bottom block of the double tall grass or double tall fern
4. Watch the top block as you break the bottom, a peony should flash where the top block was before completely dissapearing.