Dexiard (Inside Joke)

Who is Dexiard and what makes this an inside joke?
I talked about Dexiard in depth in one of my wiki pages about Dexiard. This sight gag is only shared exclusively in the sawsland friend group, that is what makes it an inside joke. There was another image of Dexiard, but I can't post it here for obvious reasons so this drawn picture of him with cope with that.