On the first watch, I considered this one to be fun, but just not as good as most of the rest of the series. Based on the lack of other comments, I suspect that opinion was wide-spread.
On the actual-for-real-rewatch after seeing the whole first season and then going through it again... this does fare better. Not only are there, as usual, jokes that I missed, such as the fact that the hat that Clayface lost his arm Indiana-Jonesing after was actually morphed out of him... meaning he actually grew a hat out of his body that could fall off, instead of just growing a hat-shaped attachment... but also, the little lost hand is less annoying and more interesting (in short, more funny!) when you're viewing the ep with a real understanding of Clayface's personality.
Clayface has already been shown to be obsessed with character motivation. I don't think Jim had that in mind when he introduced himself. However, an entity that basically has the same motivations as Clayface (1. study of acting, and 2. approval for one's self via study of acting,) but a less developed personality (therefore not many peripheral concerns about the other body's friends, or even as much shape-shifting or voice control skills,) quite probably would act like what the fist time around struck me as a rather annoying falsetto over-extended joke. When Jim introduced himself, the hand instinctively became interested in What Motivates This New Character, Jim the Cop? And from there on, progessively cast itself more and more as His Best Friend
Also, I was mildly annoyed the first time I saw this that King Shark can bite heads off this week but goes berserk if he smells Robin's blood. My take now is that smelling blood when he's in water-breathing mode drives him into a frenzy until he feeds, but smelling and/or tasting blood when he's in air-breathing mode is fine. For now, I'm going with it. It fits, and it allows sight gags like a giant shark man ducking down, still being visible be cause of his fin, and then tip-toeing up to someone who he can effortlessly decapitate in one bite.
A fate which the poor guard listening to Clayface's distraction-character's tale of woe no doubt envies.
Also, I love that among the list of potential Harley hideouts that Gordon is crossing off on his list are "abandoned mannequin factory," "abandoned chemical factory," and "abandoned 'abandoned factory' movie set."