Terry is failing his Family Studies course. His teacher offers him one more opportunity to pass: a project in which he has to take care of an Eggbaby as if it were an actual child. Unfortunately, his assigned partner Blade dumps the entire project on him. This, combined with the arrival of a new gang of villains in Gotham, forces Terry to take the Eggbaby along with him on his missions as Batman.
- Abusive Parents: Ma Mayhem towards her two sons.
- Badly Battered Babysitter: Sort of. While Terry does score an A on the assignment due to the amount of excitement and emotional stimulation he gave it, the teacher would likely not be so approving if she knew how it happened.
- Berserk Button: Do not remind Ma Mayhem that her husband abandoned her to run off with a younger woman.
- Becoming the Mask: Understated, but Howard treats his Eggbaby like it was an actual baby, much to the disbelief of his fellow "parents".
- Brawn Hilda: Ma Mayhem, again.
- Egg Sitting: Terry is forced to care for an Eggbaby for a school assignment while also working as Batman.
- Emmy Bait: Word of God admits that this episode was intentionally designed to be more lighthearted compared to the otherwise dark show in an attempt to win an Emmy award. It worked.
- Fat and Skinny: Carl and Slim, Ma Mayhem's two sons.
- Fate Worse than Death: Terry views having to take Family Studies over again would be this.
- Freeze-Frame Bonus
- When Batman hides the Eggbaby next to some sort of rooftop ventilation, a quick panout of the roof shows the shaft is not perpendicular to the rest of the building (something that Terry fails tor realize). This foreshadows that the vent is not part of the building, and is actually Ma Mayhem's getaway car in disguise.
- Right after rescuing the Eggbaby, Batman sticks his tongue out at Carl, which the baby imitates!
- Genre Throwback: In contrast to most of Terry's opponents, who tend to have advanced futuristic superpowers, Ma Mayhem is much closer to the quirky villains of the original Batman's classic Rogues Gallery.
- Gotta Pass the Class: Terry's last chance to pass his failing Family Studies class is to pass the Egg Sitting assignment worth half his final grade.
- Hidden Depths: Nelson doesn't mind the assignment at all, and takes sole responsibility for his egg (in exchange for Max doing homework for both of them).
- House Husband: Nelson takes care of the egg while Max does both of their homework, essentially making Nelson a househusband/stay-at-home dad while Max is the breadwinner.
- Hypocritical Humor:
- Bruce asks Terry how the heck he could be failing Family Studies. This is coming from the guy who never moved past the death of his parents, adopted two kids and let them tag along on his violent and dangerous adventures, ended up estranged from both of them, one of them ended up tortured and traumatized, and he's also privately tutored (instead of having ever attended public school), plus he's a playboy and never let himself settle down. Not to mention crimefighting would of course take a toll on your grades...
- Ma Mayhem telling Batman that no one hurts her boys...while stepping on Carl with her heels. And this isn't the only example of her stellar parenting.
- Instantly Proven Wrong: Terry assures Bruce that he made sure the Eggbaby will be asleep for hours and won't interfere on the mission. As soon as he finishes they hear it laughing, with it having woken up due to Ace playfully licking it.
- Karma Houdini: Minor example with Blade; she doesn't contribute to the assignment at all, but still aces it because of Terry.
- Lighter and Softer: The producers stated that they brainstormed this episode's plot by thinking of the funniest and most ridiculous plots that they could put Batman in.
- Loving a Shadow: Ma Mayhem is in such willing denial that her husband dumped her for a younger woman she believes he was a good man who suffered an untimely death. The minute one of her kids attempts to set her straight, she smacks him for speaking poorly about his father.
- Parental Neglect: Virtually, Blade proves to be a poor mother, never helping with the eggbaby and always leaving Terry to take care of it all by himself. He even calls out that he wants a divorce for her laziness.
- Parents for a Day: Terry becomes such for his Eggbaby.
- Reality Ensues: Of course Terry's grades are in trouble. He spends all his free time beating up criminals. Lampshaded by Bruce.Bruce: How do you fail Family Studies?
- Robot Buddy: The Egg Baby is a pain, but it unintentionally helps Terry a lot, crying in fear at the sight of Ma Mayhem and her sons, becoming something of an alarm when they try to sneak up on him.
- Save the Villain: Terry catches Ma Mayhem with a Batline when she falls off a roof.
- Seen It All: When Terry swiftly retrieves his Eggbaby from the dumpster where he left it, before it's hauled away by a garbage truck:
- Teen Pregnancy: What Bruce initially assumes of Terry when he first hears the Eggbaby's cries.Bruce: Terry, is there something you need to tell me?
- Villainous Breakdown: Ma starts pathetically sobbing after she watches all the jewels she stole tumble out of her purse since she stupidly forgot to turn the purse over after Batman saved her.
- Villainous Mother-Son Duo: Terry contends with a family of thieves, Ma Mayhem and her two sons, Carl and Slim, as they commit a series robberies involving valuable jewels that Ma Mayhem claims were originally hers before her former husband left her and their sons. Ma also claims at one point that she does love her sons, but will often berate and slap them for their stupidity and/or incompetence throughout the episode. Which makes for a somewhat amusing contrast to Terry, and ostensibly Bruce, as Terry was forced to become an adoptive father to the titular Eggbaby for a class assignment (and ultimately proves him to be a pretty good parent at that) that he had to carry with him throughout the entire episode. While Bruce, the stern hardass he can be, not only serves as Terry's father figure and mentor, he will go to incredible lengths to protect Terry, even at the potential cost of his own life.
- You Have GOT to Be Kidding Me!:Bruce: Even real parents with real children find ways to get away for a night.
Terry: I tried leaving it with my mom, but she said she was too young to be a grandmother.
Bruce: What about your brother?
Terry: I tried that, too. Then I caught him shooting rubber bands at it. Hey, you know, maybe you could...
(Bruce gives him a Death Glare)
Terry: Never mind.