Morty Smith (9-2184C), or Confident Morty, is a version of Morty Smith from a dimension which is, described by Rick, "full of self-assured assholes". He was brought in by Rick to help Morty flirt with Jessica, but he only made things worse.
Confident Morty is from a dimension where everyone is an asshole and no one has any regard for respect or decency. Rick retrieved Confident Morty from his dimension to be more confident than his own Morty and help him flirt with Jessica. This backfired when it turned out that all he did was spout vulgar language and graphic imagery of what he wanted to do to her, and Morty was therefor beaten up by Brad with a disgusted Jessica watching.