Trochus Hitchikers

[becky.becker]

Hello,
First time poster here. I'm having trouble identifying a hitchhiker that just showed up on my trochus snail within the past week. No new additions to the tank in a month which is part of my confusion. See attached photo but they look like white fuzzy cones. Any clue what this could be?

 

[blaxsun]

They look like pineapple sponges, but there's not enough detail to say for certain.