When I came home today, I noticed my large hammer looked odd. It is contracted and has tons of tiny particles around the mouth and in the tentacles. When I was getting ready to take some pictures one of the heads puffed up and expelled a bunch of them.
Can someone please help me identify what this is, and if there is something I should do for it?

Can someone please help me identify what this is, and if there is something I should do for it?





