During World War I, a green ball of energy smashes into the trenches, and Batman flies down from the sky. An alien invader is firing his energy cannon at the troops. As Batman tries to open fire, the German air ace, Enemy Ace, opens fire on Batman, mistaking him for the enemy. Batman maneuvers above him and says that they need to join forces to battle injustice. The Enemy Ace realizes the weapon is dishonorable and agrees to help. Together they open fire on the cannon and Batman drops a bomb, destroying it. The alien flies away and Enemy Ace salutes Batman as he departs… and hopes they don't meet again, for Batman's sake.
The aquatic villain known as the Fisherman has taken scientists hostage in their bathysphere. He prepares to kill them when their government refuses to pay the hostage, but Aquaman arrives. The Atlantean king takes out the villain and telepathically commands his whales to rescue the bathysphere. His dolphin sidekick starts talking to him, waking him up…
And Aquaman narrowly avoids a collision. He's driving an RV with his wife Mera and son Arthur, Jr. Arthur Jr. is busy playing video games and is bored with the trip. Aquaman goes back to daydreaming about his exploits, but Mera reminds him he promised that there'd be no superheroics during their family vacation. She insists that they act like normal land dwellers.
The family stops at a diner in Star City and Mera is eager to see the landmarks. Aquaman steps out and claims he's checking on the RV, but calls Batman and says he has cabin fever and needs the Caped Crusader to rescue him. Batman is busy fighting the Penguin's henchmen and tells Aquaman to enjoy his vacation. As Aquaman goes inside, the Arrow Signal flashes across the sky.
The Clock King and his henchmen are robbing the Star City Bank when Green Arrow arrives. Aquaman shows up to help but Green Arrow insists he can handle it. The Clock King escapes while his henchmen cover his exit. Aquaman takes them out and Green Arrow nets them with an arrow. They follow Clock King to a museum where he takes a hostage. Aquaman telepathically commands some lobster to attack him and the day is saved. Aquaman returns to have some apple pie with his family.
Next, Aquaman and his family visit a tourist cowboy town. Aquaman claims that he's feeling land sick and puts his wife and son on a stagecoach tour… and then calls Batman again. Batman is still busy tracking down the Penguin through the streets of Gotham City and hangs up. Aquaman hears a news report about the Blue Beetle battling the Planet Master at a nearby gold mine and goes to investigate.
Planet Master is using the power of the planets to hold off Blue Beetle. As they argue over whether Pluto is a planet, Aquaman arrives and knocks back the villain. Blue Beetle is glad to see one of his idols and the two of them team up to deflect his meteorite strike back at him. Aquaman invites Blue Beetle to visit him in Atlantis and even starts to let him title the adventure before driving off in his RV.
The Aqua family arrives at the hotel, but Mera catches a newscast about the battle. Aquaman admits he couldn't help it but gives his kingly word that he won't do any more heroics.
The trio travel across the country, and Arthur Jr. is still bored. They drive past a battle between the Top and the Red Tornado, but Aquaman's services aren't required. At another stopover, he witnesses Dr. Polaris and Green Lantern fighting, but Aquaman keeps his word. He even sees Sportsmaster… on vacation with his family.
Finally the family arrives near Gotham City. Aquaman gets a call from Batman's communicator, but discovers that the Penguin has captured his arch-nemesis and strapped him in a giant deathtrap with a dipping bird. Aquaman realizes that Batman finally needs his help. Aquaman drives them to Gotham City without telling Mera what is going on. She soon realizes that he's there to see Batman. He follows the communicator signal and goes into the warehouse where Batman is being held. Penguin electro-shocks Aquaman unconscious, and then sends his henchmen to capture Mera and Arthur Jr. when they come in to investigate.
All four of them are strapped to the conveyer belt and Penguin boasts that he will send his umbrella drones across the city to fire paralytic gas and knock everyone unconscious. Aquaman apologizes and Mera admits that perhaps normal vacations aren't for them. The Penguin interrupts to fire his drones across Gotham City. Mera tells Aquaman to show her husband why he's king of the city. Aquaman telepathically commands crabs to climb up, get Batman's utility belt, and give it to the Caped Crusader. He uses it to free himself and throws a Batarang to stop the conveyer belt. Aquaman frees his family and they join with Batman to battle the Penguin's henchmen. Batman takes the Penguin's control unit and shuts down the drones, and the villain flees. Batman goes after him and Mera tells Aquaman to help.
Batman goes off the pier in the Batmobile, transforming it into a sub, and catches up to the Penguin as he boards his sub. Aquaman swims up and arrives in time to lend a hand, and the Penguin opens fire with a flamethrower umbrella. Batman entangles it with his cape and knocks the villain out once and for all.
Later, Batman thanks Aquaman for his help. The Atlantean king then says it's time for a real vacation. Mera and Arthur Jr. would rather see him save the world again.
Mera first appeared in Aquaman #11 (Sept. 1963) and was created by Jack Miller and Nick Cardy. A queen from another dimension, Mera fled to Earth's reality after an usurper took the throne. She met Aquaman, who aided her, and the two fell in love and married. They had one son, Arthur Jr., who in the comics died at the hands of Black Manta. This created a rift between the couple that has waxed and waned over the years.
Oswald Chesterfield Cobblepot first appeared in Detective Comics #58 (Dec. 1941) and was created by Bill Finger and Bob Kane. An odd-looking child, Oswald's mother forced him to carry an umbrella at all times to avoid catching colds in the rain. He also had a love of birds. When he became an adult, he began a life of crime using these two obsessions and a childhood nickname based on his appearance to become the Penguin, Batman's arch-enemy. He has since appeared regularly for 5+ years and has been seen in television and movies. In recent years he has given up a life of direct crime and instead become a night club owner, black marketer and informant.
Hans von Hammer first appeared in Our Enemy At War #151 (Feb. 1965) and was created by Robert Kanigher and Joe Kubert. A brooding German nobleman, von Hammer flies a Fokker Dr.I during World War I and battles the British. Von Hammer is of noble blood and considers himself a flying knight. Unlike the Red Baron, Von Hammer lives past the end of the war, fights in World War II (out of loyalty to his country rather than embracing the Nazi cause), and lives until 1969. This is his first animated appearance.
The Fisherman first appeared in Aquaman Vol. 2 #21 (May 1965) and was created by Henry Boltinoff and Nick Cardy. This unidentified thief uses enhanced fishing-based equipment such as a titanium fishing rod and line, and explosive lures, to rob ships and coastal cities. His activities brought him into conflict with Aquaman, and they have battled many times since then. He was apparently killed during Infinite Crisis, but it was later revealed that his helmet is a parasitical creature that takes various host bodies and uses fear to force them to commit crimes.
Professor Norbert first appeared in Detective Comics #296 (Oct. 1961). Norbert was exposed to meteor gas and became a villain due to a shock to his mind. Using his knowledge of astronomy, Norbert became a costumed villain and battled Batman. When the gas warned off, Norbert joined forces with Batman. Later, the terrorist Kobra gave several individuals powers similar to those of earlier Batman villains. An unnamed member of Kobra's Strike Force was given a suit that gave him the powers of all the planets. This is his first animated appearance.