Well, I suppose one could do that, but it’s rather stupid. We don’t call them all “dubiouses” just because one of them is “dubious”.
They have a name: they are a version of emoticons, Japanese style ones called kaomoji. Our you can call them “smilies” if you’re determined to use the basest vernacular.
The OP posted several formats of one kaomoji, one that is shrugging. He pluralized that, since he had more than one.