こいつ　そいつ　あいつ vs こやつ　そやつ　あやつ


I know they're all connected to 奴, but what's the difference? Are the forms in
～やつ more old-fashioned?




Yes, ～やつ is antiquated and one would only use it in a joking manner. E.g.
`こやつが犯人です` as a caption for a funny cat pic.




Yes, ～やつ is antiquated and one would only use it in a joking manner. E.g.
`こやつが犯人です` as a caption for a funny cat pic.

