http://tvtropes.org/pmwiki/pmwiki.php/Recap/BatmanTheAnimatedSeriesE6TheUnderdwellers
Batman discovers a group of homeless children forced to steal for a cruel, deranged man called the Sewer King.
Tropes in this episode include:
- Absurdly Spacious Sewer: The tunnels are larger than the average hallway, and some chambers are huge and cavernous.
- Abusive Parents: The Sewer King sees himself as a good parent to his "beloved children", even though he orders them to steal for him, punishes them severely for talking, and makes them live in deplorable conditions.
- Adaptation Dye-Job: The Sewer King's hair was black in his original appearance, but red during his appearance in the comics.
- Big "NEVER!": Batman tries to catch a falling Sewer King from falling into Sewer Gator-infested waters, only to be greeted with this. Sewer King shows why pretty quickly - those gators are his pretties, and they just obediently pull him to dry land.
- Break the Haughty: We're introduced to the Sewer King as a shameless, Hot-Blooded tyrant whose mere presence has dozens of orphans quivering in fear. A furious Batman eventually chases him down and gives him a strongly-worded threat, and this time, Sewer King is the one shaking in his boots.
- Day Hurts Dark-Adjusted Eyes: The Sewer King locks his slaves in a room with painfully (to them) bright lights as punishment. When they are finally freed, they are dazzled by the daylight, but it's apparent that they'll get used to it as they're returned to normal lives, if Frog's excited reaction is any indication.
- Evil Cannot Comprehend Good: The Sewer King can't understand why Batman would bother saving his life. See Papa Wolf below for Batman's reasoning.
- Evil Is Petty: When Sewer King discovers Frog is missing, he goes into a screaming rage (a-gain), overturns his table with all the food on it, and tells his children that there'll be no food until Frog is found. That's rich coming from someone who wasn't sharing any of his food anyway.
- The Fagin: The Sewer King is the evil version.
- First Time in the Sun: In the end, the Sewer King's captured orphans are brought into the sunlight at last.
- Friend to All Children: This is the first episode to show Batman's soft spot for children, displayed when he expresses a desire to kill the Sewer King for his abusive treatment of them.
- Green Gators: The Sewer King's alligators are green.
- Hate Sink: From his whiny, nasally voice to his penchant for throwing ugly tantrums, the Sewer King doesn't seem to have any redeeming qualities. His brutal treatment of innocent children makes it clear he's just an all-around horrible, piece of crap excuse for a person.
- Honor Before Reason: When Sewer King is falling into his alligator pit (but then again, maybe he just knows his alligators wouldn't attack him).
- Hypocrite: The Sewer King calls Batman a "costumed freak." Please; he has on some hacky pirate outfit, and he's taking shots at Batman?
- King of the Homeless: The Sewer King.
- Large Ham: The Sewer King demands the children remain silent. Himself, on the other hand...
- Lessons in Sophistication: There's a comedic subplot of Alfred, whom Batman leaves Frog with, attempting to do this for the disheveled young lad. He helps to clean Frog up, then tries to teach him table manners and gets him to help out in the kitchen. As expected for a kid with a warped view of morality, who's spent who-knows-how-long on the streets of Gotham, Frog refuses to take him seriously, even stealing silverware the moment Alfred's back is turned. That's just how Street Urchins roll. Batman eventually sets the kid straight.
- Light Is Not Good: The Sewer King punishes a child for breaking his rule against "talking" (he cried out after injuring himself) by locking him in a room filled with bright lights for several hours. Averted at the end when the orphans enter the daylight again.
- Minimalist Cast: This episode has the smallest credited cast of the entire DCAU, with only four names listed.
- Minor Crime Reveals Major Plot: While he makes his rounds on a typical evening, Batman overhears police talking about a "leprechaun" that stole some lady's purse. This "leprechaun" is Frog, who eventually leads Batman to an underground child slavery ring.
- Monster of the Week: The Sewer King is a one-shot villain, who never appears again. He is sufficiently creepy for a Batman villain, but it's just as well he never returns, since he is really only good for one story (that is, showcasing the evils of child slavery). Taken in-universe, after that chewing-out at the climax from Batman, one can easily imagine the Sewer King probably wouldn't want to get out of jail for a long, long time.
- Mook–Face Turn: Frog is the first one to publicly turn on Sewer King when he saves his friend from a hostage situation. To be fair, none of them were really bad kids - they were just being used and corrupted by a truly repugnant human being.
- Mook Horror Show:
- A kid's version, as Frog attempts to escape Batman through the sewers that he knows like the back of his hand, only to find there is no escape from the Dark Knight no matter where he goes.
- The Sewer King has an adult version as he learns to his growing terror how relentless Batman can be when he's chasing a villain down.
- Mythology Gag: Batman's line "I think this is a job for Batman" is a likely homage to Bud Collyer, who credited the phrase "This looks like a job for Superman".
- Never Smile at a Crocodile: The Sewer King trains alligators to use as attack hounds and bodyguards; in fact, he's really not much of a threat without them.
- No Indoor Voice: "Rule number one... NO TALKING!!!!"
- Papa Wolf: Batman is enraged by Sewer King's crimes against the orphans. He's so angry, in fact, that he's extremely tempted to actually break his Thou Shalt Not Kill code.
Batman: I don't pass sentence. That's for the courts. But this time—this time I am sorely tempted to do the job myself!
- A Pirate 400 Years Too Late: The Sewer King; if his boasts of "caring" for these children aren't enough to clue you in on how delusional this guy is, his slightly ridiculous pirate outfit will — albeit with the traditional eyepatch replaced with a pair of sunglasses with a missing lens.
- Reckless Gun Usage: While being chased by Alfred in the Wayne mansion, Frog finds a collection of antique firearms. He grabs a blunderbuss off the wall and waves it around like a toy. Alfred immediately backs off, but Batman jumps in and grabs the gun out of the boy's hands. Batman notes, "It's not loaded, but it could have been."
- Save the Villain: Batman saves the Sewer King from being hit by a subway train. When the astonished villain asks why, Batman responds that he leaves judgment and execution to the courts. Batman is still sorely tempted to make an exception here, what with the nature of the otherwise silly-looking villain's crimes.
- Sewer Gator: The Sewer King has somehow tamed an army of these. They are so loyal that they don't attack him when he falls into their pool.
- Slavery Is a Special Kind of Evil: Child slavery, even more so. Batman is so horrified and angered by the conditions the children are kept in that he seriously considers breaking his Thou Shalt Not Kill rule.
- Somewhere, a Herpetologist Is Crying: It's extremely unlikely that Batman, even at his peak strength, would be able to overpower the bite of an alligator (which may reach almost 3,000 lbs in bite force). He'd be much better off holding the gator's jaws shut; the opening muscles are far weaker.
- Street Urchin: A whole collective of them.
- Suddenly Voiced: Frog gets a single line at the end of the episode, when he's one of the first kids rescued by authorities.
Frog: [rubbing eyes at the morning sun] ...the light.....
the light!!! - Symbolism: Throughout the episode, the children (Frog among them) dread light, as the Sewer King likens it to the families who either abandoned them or mistreated them. During his first morning at Wayne Manor, Frog retreats from light as Alfred draws the curtains to greet the morning, as though signifying the boy has yet to accept there are better people out there. After the climax, Frog and the other children are able to savor sunlight as Child Services and the Police help them out of the sewers, reflecting that they're ready to reenter society despite the Sewer King claiming they could never be accepted.
- Thou Shalt Not Kill:
- Batman still goes by this, but he let the Sewer King know that he was "sorely tempted" to break it after seeing the villain's treatment to the orphans.
- Notably, when they're fighting earlier in the episode, Batman inadvertently causes the Sewer King to fall into the pool of water they're fighting above. Batman sees the alligators going into the water after him, thinking that they're going to eat the Sewer King—and Batman simply comments on how appropriate a fate it is for him. Only to hear mocking laughter coming from the other side of the room.
- Tranquil Fury: Batman, when he sees the conditions the children live in. His eyes squinting and his jaw clenching are his only visible expressions that he's quaking with rage, a reaction that not even the Joker has roused in him.
- The Voiceless: The Sewer King, believing that children should be seen and not heard, forces his charges to be silent at all times... or else.
- Would Hurt a Child: Dear lord. The Sewer King keeps them as slaves and treats them like dirt. Hell, he locks them in an extremely brightly-lit chamber when they get on his bad side (not that he ever has a particularly good side). The most despicable part may be his claim that he's helping them. Either that or how he threatens to feed a little boy to his gators just to get under Batman's skin.
- You Have GOT to Be Kidding Me!: Batman has this in his tone of voice when the Sewer King shows how deluded he is.
Sewer King: You've caused me great distress, you evil bat! Yes yes yes, you have! You've hurt my pretty pets! And you've frightened my beloved children!
Batman: [disgusted] Beloved children?!?
