I'm pretty late to this, but here is the Conan O'Brien clip in which Triumph the Insult Comic Dog visits the San Diego Comic-Con. You'll note that Smigel never used the interview I saw, with long-haired Joker.
While seeing Triumph deliver his insults on TV can seem mean, watching the filming reveals that Smigel himself tempers that -- you can't see his face, but he's smiling and chuckling through the whole thing.
And I think I happened to see his last interview of the day. After he wrapped up, he stood around posing for pictures, signing things, and kidding around with everyone. For a long time. I watched for a while, walked away, talked to some friends, and when I walked by later, Smigel was still there.