Bad mushroom. Even better it found a its our body guard to hide behind LOLAre you taking about my post with the red cage?
If yes - the colony grew and I occasionally get a mushroom in a random place. In this case, my sandbed near the colony. The mushroom is not attached to anything and has been in the same spot for weeks. Until the day after I included it in a sale. I checked the tank the day after and the mushroom was gone lol. I found it behind a rock. Grabbed a bristleworm by accident trying to fish out the mushroom. About 50+ bristles in my finger. Lol. Then I decided the mushroom will be caged until it’s packed and shipped.
They normally don’t move around, after they are attached to rock and settled in