Compared to most of the more recent DCAUO-movies, Batman and Harley Quinn has a much more comedic tone to it:
- While doubling as heartwarming, the tactic that Harley uses to convince Poison Ivy to turn against Floronic Man's plan to turn the humans and animals of earth into plant hybrids: Puppy-Dog Eyes combined with Cry Cute.
Ivy: (sobbing) I hate you so much.
- Making it even funnier: Ivy knows it's coming and begs Harley not to unleash the expression on her.
- Doubling as an awesome moment, the idea that Harley Quinn and the Dynamic Duo go with to ultimately defeat him: setting him on fire (since he's made of plants). When the Floronic Man is shown in the first stinger, he's running around screaming (after being lit on fire).
- This exchange between Batman and Harley shortly after she's recruited by the Dynamic Duo:Harley: Do you know what I am?
Batman: My punishment for dropping out of med school.
Harley: Eh, wrong!
- Harley blubbering and begging to help Bats and Nightwing because she doubts she could survive "the veggie apocalypse."Harley: WHAT IF I FORGET TO WATER MYSELF?!
- Harley's reaction to Swamp Thing showing up at the end and doing absolutely nothing to stop Jason.Harley: Well that was a big ass bucket of nothing!
- Batman's reaction to Harley's farts.Batman: It's not so bad, it smells like.....discipline.
- Batman's expression later on as it appears that Discipline smells really, really bad.
- And Harley's just sitting there smiling smugly as Nightwing and Batman are suffering.
- When they stop at the gas station, Nightwing offers Batman $10 to leg it without her. Did he forget that Batman's a billionaire?
- The Bad-Guy Bar sequence, which has shout outs to the 1960's Adam West show and highlights Batman's status as the Not So Above It All comically serious.
- Harley flipping off shrubby before singing a cover of "Hangin' on the Telephone" by Blondie.
- Batman tapping his fingers to the beat of the song, stopping immediately when he sees Nightwing grinning.
- Just the fact that Captain Clown is at the bar and dancing with a woman. Added fun is that the "woman" is Randa Duane, an android. So two robots sharing a dance.
- When the mook is mocking Batman by making faces and doing the Batusi behind his back, they let it go on long enough that the audience knows the Offhand Backhand is coming.
- Batman's reaction to seeing Nightwing doing the monkey with a girl.
- Immediately thereafter, Batman is contacted by Booster Gold, who offers for several B-list and C-list heroes to come and help Batman. Bats and Nightwing, using sign language (including the "jerk-off" gesture), unanimously agree to turn down every hero offered and produce Fake Static to ditch Booster after he offers to come help them himself.Batman: (as Nightwing crumples a burger wrapper) Sorry, Booster, we're passing under... high tension lines.Booster: That sounds like paper.
- Harley sniping at Batman for not having bug-spray in his utility belt. Rather than silence or a return-quip, his bewilderment at the suggestion implies that the poster boy for Crazy-Prepared never even thought of something so mundane.
- "So your Plan B is Harley Quinn?" *Beat* "God help us."
- "This is no ordinary leafy mouse... but the HARBINGER OF A NEW AGE!" Even the Floronic Man (who?) gets one.
- Floronic Man nearly forgets the duffel bag of research materials and chemicals when he and Poison Ivy use a tree to teleport to Louisiana.
- Batman Sherlock Scans the room, then gives Nightwing a Disapproving Look over the blatant signs that he's slept with Harley, causing Nightwing to mutter, "Like you never made out with a supervillain..."
- Nightwings mental gymnastics in convincing himself that sleeping with Harley is actually for the good of the mission.
- When Harley is trying to talk Ivy out of her plan to turn everyone into plants.Harley: You wanna save the world? Go Democrat! Join Greenpeace!Ivy: That's for whales, you moron!
- The ending. Harley has a health show like Dr. Phil...but with a twist: it's also a wacky game show similar to Double Dare!