Long time ago I had a mushroom visitor, but it was something that finds its way to flower pots from time to time. This time Google seems to be really confused as to what it might be. At least all its suggestions show mushrooms that are not edible, however every single one has something that doesn't fit. Be it size or color, or how the cup turns concave in bigger (older?) one. Anyway, I've prepared some pictures, so someone might notice what it is.
Let's test if all front-ends support spoiler markdown (meh! ecency does not 😞).
! [Solved] JK, JK :o) It is actually a coral that I bought last Saturday on mineral fair and the stem is made of paper straw.