I had a rabbit attachment. It isn't sold on the site but it was blue and silicone. It was SO LOUD. The Hitachi is already loud but I felt like my neighbors could hear it with the attachment on. There was a similar one that was sold on the site but I can't find it now. I used it about twice and then I decided that I didn't like the Hitachi and retired it to be a back massager.
I bought it for $35 at a local adult store. I kind of want to list it on the classifieds for an extremely discounted price so someone else will get something out of it. It is silicone so I don't feel gross selling it.