Tumblr interface question

Is there a way to block the gross porn bots on Tumblr, that sometimes follow you, without having to visit their page? You can usually already tell from their icons when you're notified so I really don't need to see a full screen of their stuff. Except that is the only place I know how to get Tumblr to display the blocking option, especially in its mobile app but I think this applies also to the desktop version. That site's interface is such a burning trash fire...