Ghost types are the most enigmatic of all types, they dodge common sense and are absolute pranksters by nature.
With that on mind I just feel people don't give Decidueye that credit. And what makes this owl even more special besides being the first starter to be part ghost type, is the fact it is the only pokemon alongside Froslass and Alolan Marowak that literally becomes a bizarre spirit though evolution instead to be born as one.

I do know the reason behind that, Decidueye is based from an extinct hawaiian owl species. But well its design is pretty shady itself!
So why not be more besides a sophisticated archer? Man this dude has potential!