ID unknown hitchhiker (coral? pest?)

[c_scherer123]

Originally Posted by Myka

Does it react to light or you touching it (use feeding prongs or something in case it is toxic)?

If it does react I'm leaning more towards an anemone. If it doesn't react, and is unchangable for the most part from one day to the next then I vote for sponge/tunicate too.

I used a glasseye dropper (used for feeding frozen food) and gave it a thorough poking - absolutely no reaction, other than being slightly crushed. It was hidden behind some mushrooms and I thought it might have been a majano, but it wasn't until the mushrooms retracted some that I got a clearer look.
But what got me confused is that it doesn't look like the sponges I am used to seeing (not that I have seen many varieties yet). It almost looks 'feathery'.