CREDITS: Written by Stan Berkowitz (key DCAU writer who would go on to write for animated DCU projects beyond the DCAU); directed by Kenji Hachizaki (animator on such anime projects as Akira and Howl's Moving Castle).
REVIEW: Metallo is one of Superman's key villains, and John Corben was seeded in the pilot, so... what went wrong? Both script and animated execution seem badly thought-out. Making Luthor the mastermind behind Corben's transformation is a good idea, and keeps Lex at the forefront of the Man of Steel's problems, but was there REALLY a need for a rare virus apparently contained on a small island somewhere, yet known to Lois Lane? He'd bought the prison doctor, the man could have claimed anything. He need not have poisoned Corben. We could then have avoided the scene where Lex screams mouth open while Metallo splashes the virus all over his face. Even if you need the idea of the virus to drive a wedge between the two villains, it need not have been REAL.
But then this is yet another episode where the bad guy keeps punching Superman AWAY from the kryptonite, only showing it off as a ranged attack in the climax. Where Lex's bikini'd girlfriend is sent below decks on the yacht, then not seen again and potentially left to drown when Superman sinks the boat. Where Superman borrows a fisherman's net and never brings it back. Where a promise is made to have him return to take revenge on Luthor, but on the show at least, it never happens. Where the action is only okay, and the humor derives from tasteless double-entendres (oh Mr. Luthor, it's so biiiig - the yacht - and Metallo implying he was jerking off to thoughts of Lois Lane in his cell before sexually assaulting her - ick). And then there's Superman flying off and leaving Luthor to the ocean, only returning to put a button on a shark gag.
I certainly do like Luthor's fearlessness (now if he can stop bragging about how it's impossible to pin anything on him before Superman starts carrying a tape recorder), and there's an attempt at tracking Metallo's disconnectedness to his humanity (if only he hadn't been a psychopath to begin with). By making him a madman, he at least becomes more interesting that if he'd stayed a simple physical threat, though it does put him at the halfway point between Mr. Freeze (mentally) and Two-Face (physically). Not quite original in either sense.
IN THE COMICS: Metallo first appeared in Action Comics #252 (1959), but the look adopted here is from his post-Crisis days. Originally, he was a journalist on the run for a murder he committed, and then involved in a near-fatal car accident. He was found by a Dr. Vale (same name as his prison physician on the show) who placed his brain in a robot body. Because his uranium heart would only power his body for a day, Corben stole a piece of longer-lasting kryptonite and became Metallo. In his civilian identity, he briefly tried to romance Lois Lane, echoed in the animated scene where he forces a kiss on her here. The post-Crisis Metallo has similar origins though he was merely a con man before the accident. His Dr. Vale thought Superman was the spearhead of an alien invasion and told Metallo to destroy him. In a reversal of this episode, Lex TOOK the kryptonite from him. In the New52, Metallo is under General Lane's command; it is suggested he and Lois used to be involved.
REWATCHABILITY: Medium-Low - A disappointment, even if it had all the elements required to work.