While on a desert highway, the RV gets stolen by a group of modern-day pirates, who use it to go on a robbery.

After being in contact with water from the Fountain of Youth, Grandpa Max and Ben are reverted to being kids again. Now, Gwen is left to take care of them while stopping Hex from finding the fountain's source.

Ben gains another Omnitrix hero to use, which he calls Ditto. Gwen can't stand being around the multiplying Dittos, and they end up giving her headaches. The Dittos, though, prove to be real helpful against Dr. Animo and his multiplying Stinkflies after he extracted some of Ditto's DNA.

Ben, Gwen, and Grandpa Max attend a family wedding. During the ceremony, a strange alien attacks. Will the two ever finish this strange wedding?

Enoch and the Forever Knights return, putting Ben in a dream world where he's tricked into having the perfect day. However, his dream quickly turns into a nightmare.

During a battle with Dr. Animo, the Omnitrix is accidentally set to self-destruct. In order to stop it, Ben, Gwen, and Tetrax travel across space to track down the Omnitrix's creator, Azmuth.

When Ben accidentally breaks Gwen's laptop, he participates in the "Ultimate Wrestling Competition" as Four Arms to get the prize money for a new laptop to replace Gwen's broken one.

Ben, Gwen, Cooper and Grandpa Max face their last battle ever against the villains they have encountered and they will battle to get the world's most powerful energy source.

Ben, Grandpa Max, and Gwen come upon a bizarre Christmas theme park run by an evil entity who thinks Grandpa Max is Santa Claus and proceeds to trap him.

During a battle with Dr. Animo, the Omnitrix is accidentally set to self-destruct. In order to stop it, Ben, Gwen, and Tetrax travel across space to track down the Omnitrix's creator, Azmuth.

During a battle with Dr. Animo, the Omnitrix is accidentally set to self-destruct. In order to stop it, Ben, Gwen, and Tetrax travel across space to track down the Omnitrix's creator, Azmuth.

The Forever King sets his plan in motion and recruits the most powerful enemies Ben has ever faced in order to steal the world's most powerful energy source.

Ben discovers an evil circus that's headed by a psychic vampire clown named Zombozo.

At a museum, Ben sits and reads a comic, daydreaming about himself as a super hero. As Gwen interrupts him, she is not happy how Ben treats the artwork. His day has been a bore, but when an alien vessel arrives, an alien named Volcanus and the bounty hunter Sixsix come to pursue the Biocenthium alloy to complete a mixture with Element X to create a bomb, strong enough to destroy a whole solar system. Suddenly, Ben meets The Galactic Enforcers, a group of three who serve in protecting the galaxy under the conduct code. Ben is intrigued by their heroic appearance, but are they really something to be looking up to?

In the future, Ben gives his son, Ken, an Omnitrix for his 10th birthday. However, Ben will have to learn to trust him with that power.

Ben has his hands full with a giant sea monster and an evil poacher.

Ben must rescue his aunt and grandfather when they are held hostage by shape-shifting aliens.

Ben battles a sorcerer who possesses a number of charms, and Gwen suddenly becomes a superhero when one of the charms falls into her hands.

After the battle with Vilgax, Grandpa Max retells his story to Ben about his past. He was with an organization that was not known to exist, referred to as "The Plumbers," a group of people who track down extraterrestrial life. Meanwhile, they meet Phil, an old partner of Grandpa Max. But they soon find out that he steals a device, called the Null Void Projector, to selfishly use it to make money by appearing to capture aliens that he alone released himself.

At Yellowstone Park, Ben and Gwen inadvertently discover a new form on the Omnitrix: Cannon Bolt, an armadillo-like alien that Ben isn't too fond of. Soon after, a meteor comes crashing down to the park, containing a planet-devouring, tick-like alien. On top of that, three other aliens arrive with it, and worship it as their savior, the "Great One." Powerless to stop the planet-eater with his regular forms, Ben must rely on a new form he knows nothing about.

Our heroes ride a jet belonging to Grandpa Max's old Friend, Donovan Grand Smith, who owns an underwater resort. At the entrance, they receive a warm welcome from Donovan himself, though they also meet with his grandson, Edwin, who didn't seem to be excited about their guests. Later, when Edwin, Ben, and Gwen enter the Undersea Manta Ray, a giant submarine, they encounter strange aliens that threatened to destroy the whole resort. While the kids find a way to cooperate with each other to find the source that lures them in, Donovan himself learns a few lessons in how to bond better with his grandson.

The Tennysons stay in as it rains outside, and Ben plays a video game to pass the time by. When Gwen decides to join in, Ben is jealous of how she's a far superior player. Instead, Ben decides to transform to Upgrade, and merges with the game console. Gwen makes an attempt at shaking him off, but suddenly, a lightning strike causes them to transfer into the video game itself. The only way Ben can use the Omnitrix is to find coins with the different aliens on it. To get out, they must find the Upgrade coin before an evil being uses it to escape into the real world.

Ghostfreak's return spells disaster for our heroes. Grandpa Max and Gwen must deal with the mummy alien in space while Ben deals with Ghostfreak and Dr. Vicktor on Earth. Ghostfreak then reveals his master plan: he plans to blanket the Earth with Coronium so that sunlight will not reach the planet so that he may rule. With the power of a new alien in the watch, can Ben stop Ghostfreak, and save Grandpa and Gwen?

While snowmobiling, two guys accidentally release an alien named Xylene from a strange container. At a park, Ben (as Wildmutt) steals Gwen's kite, so she casts a spell to make dogs attracted to him. Grandpa Max seems sad to be in St. Louis since it is where he met his wife. Xylene attacks, and Grandpa Max comes to defend, only to recognize her. Xylene reveals that she came to find the Omnitrix since she lost it when Vilgax attacked her ship. While Grandpa Max and Xylene talk about the past, a robot emerges from the area where Xylene was and attacks Ben and Gwen. The mechadroid attacks twice, taking Grandpa Max with him. Now Ben must work with Xylene (to his dismay) to save Grandpa Max.

Ben must fight Dr. Animo, a crazed scientist who has a DNA-altering device.