Although fan excitement is usually measured by the viewers a trailer receives, number of characters crammed into the footage might also be a good metric. If so, then the response to the Comic-Con International trailer for DC Universe's Harley Quinn animated series is off the charts. Even the trigger warning for explicit language, adult themes and violence is an implicit shout-out to fans -- especially those who understand that cartoons aren’t just for kids. If that warning wasn’t enough, give the trailer just a few seconds. Voiced by Kaley Cuoco, Harley announces herself with “It’s me, dickhead." The dickhead in question is, of course, none other than The Joker.

The series will chronicle Harley’s pursuit of supervillain cred in the form of membership in the Legion of Doom. And from the trailer it looks like her squad features some of the quirkier characters in the DC Universe. Here is an exhaustive (if not fully complete) list of characters that appear in the frenetically paced footage.

RELATED: Harley Quinn's Katey Cuoco Teases Animated Series With New Art

A Special Class of Villain

The first snapshot of Harley Quinn’s aspirations comes fairly early on in the trailer. From left, these are the legendary DC villains that Harley sees as her role models. Penguin, Scarecrow and The Riddler almost need no introduction; they've established their bona fides through their confrontations with Batman across comics, animated and live-action television, film and video games. The mysterious robot in the background is either Superman foe Brainiac or the more-obscure Cyborg villain Grid. Lastly, is Aquaman’s longtime nemesis Black Manta, and the Scarlet Speedster's opposite number, Reverse Flash.

Hello, Puddin'!

It's Harley's break-up with The Joker that sets her on her path to join the Legion of Doom, so of course "Mistah J" plays a prominent role in the trailer. "It's me, dickhead," she deadpans, setting the tone for their rocky relationship in the animated series.

DC's Sea King

Speaking of Aquaman, the king of Atlantis makes a couple of cameos in the trailer, confirming that the scope of Harley Quinn’s aspirations is not limited to the world of the land dwellers.

Harley’s Squad

From the looks of the trailer, Harley will work closely with several under-used characters. Her immediate team seems to be comprised of the classic Batman villain Clayface, and Doctor Psycho, one of the original members of the Secret Society of Super Villains.

The Proof is in the Poison

It wouldn’t be a Harley Quinn adult animated series without the presence of Poison Ivy, whose modern relationship (and, yes, romance) with Harley Quinn has become a favorite with fans and creators alike.

Have You Seen These DC Villains?

Figuring out all of the characters in this little trailer is complicated. King Shark, whose profile has raised in recent years because of his appearance on The CW's The Flash, will have a role in Harley Quinn. The identity of the cigarette-flicking mouse is anybody's guess. The mysterious women with them may be Kuasa, the older sister of Vixen.

A Different Sy-Borg

Sy Borgman worked with the U.S. government to thwart Russian terrorists. Eventually he connected with Harley and, at least for some time, lived with her. This version of the character is ready for more comic relief in the series.

Give the Commissioner a Hand

It's Gotham City, so of course Commissioner James Gordon has a role to play in Harley Quinn. However, it's unlikely anyone expected to see Batman's longtime ally enjoying a game of poker, and a laugh, with Clayface.

Luthor Doesn't Seem Like a Fist-Bump Guy

Perhaps just as unexpected is the first-bump shared between Lex Luthor, arguably the premier supervillain in the DC Universe, and KGBeast, who is only now, three decades after his debut, beginning to earn some degree of respect.

The Guy Who Started It All

The age-old debate is whether Gotham City's cast of colorful rogues would even exist if it weren't for the presence of Batman. Does the Caped Crusader merely fight them, or does he also attract them? The question may never be satisfyingly answered, but in the meantime we can enjoy such colorful criminals as The Joker, Scarecrow, The Riddler and Kite Man.

Kite Man, Hell, Yeah!

Yes, Kite-Man, the old-school Batman villain who's been the butt of countless jokes since his introduction in 1960. However, in recent years the character has enjoyed something of a resurgence with prominent roles in the DC Rebirth era of comics, and in The LEGO Batman Movie.

Villains Galore

In another glimpse of Harley’s desired affinity group, several more well-known supervillains pay a visit to Atlantis to see Aquaman take a heel to the face: Black Manta, Captain Cold, Two-Face, Cheetah, Calendar Man (in his more traditional garb), and, of course, Poison Ivy.

Premiering in October on DC Universe, Harley Quinn stars Kaley Cuoco, Lake Bell, Diedrich Bader, Alan Tudyk, Rahul Kohli, Christopher Meloni, Tony Hale, Ron Funches, Wanda Sykes, Natalie Morales, Jim Rash, Giancarlo Esposito, Jason Alexander and J.B. Smoove.

KEEP READING: Harley Quinn Takes a Shot At Deadpool in First Teaser for Animated Series