Owzer's house in Jidoor, yeah. It might be nice to go get the Bum Rush before you go to get Relm, though, because it makes the fight a lot easier.

That's not to say it's overly tough, but you have to be patient. It has two forms, and I'm sure you'll figure out which one you need to pound and which one to try and avoid attacking. And remember that Regen comes in handy.