This is several individual barnacles that can be printed separately.  I was putting these on a costume and found that it was really difficult to find barnacle models in general and even tougher to find individual barnacles.  So I'm uploading the ones I put together so that hopefully someone else can benefit from them.  I used two of the models in this plate, I've thrown in the third one just in case it's useful to someone

I found that brushing on some very watery brown paint and dabbing off the excess with a paper towel gave me a good look