The BEST Episodes of Ben 10: Ultimate Alien

Every episode ever - ranked by fan votes!

Last Updated: Aug 24, 2020

Network: Cartoon Network

Taking place a few weeks after where Ben 10: Alien Force leaves off, Ben 10: Ultimate Alien follows the now sixteen-year-old Ben. The Omnitrix has been destroyed and Ben must learn to master the secrets of the new Ultimatrix, a gauntlet-like version of the old Omnitrix that not only gives him access to all of his original powers and abilities, but also allows him to evolve his alien forms into even stronger and even more powerful versions (called "ultimate forms").

Ben 10,000 Returns

#1 - Ben 10,000 Returns

Season 2 - Episode 10 - Aired Apr 15, 2011

Following a visit from Paradox after a fight with Eon, Ben 10,000 arrives 20 years from the future to seek the aid of his past counterpart in tracking down Eon.

star 8.74
258 votes
Solitary Alignment

#2 - Solitary Alignment

Season 2 - Episode 23 - Aired Dec 9, 2011

Azmuth reveals how Old George got his sword and slayed Diagon.

star 8.48
118 votes
The Ultimate Sacrifice

#3 - The Ultimate Sacrifice

Season 2 - Episode 19 - Aired Oct 28, 2011

The ultimate aliens inside Ben's Ultimatrix demand their freedom!

star 8.44
132 votes
Escape From Aggregor

#4 - Escape From Aggregor

Season 1 - Episode 5 - Aired May 21, 2010

In the Himalayas, Dr. Animo and his mind-controlled Yeti were fighting with Ben. Ben, as Brainstorm, mind-controls the Yeti and frees him. Kevin and Gwen deactivates the Devalution bomb. Gwen calls the Plumbers to take them, the Plumbers informed them that there is an alien action in Bellwood. Ben encounters the turtle-like alien Galapagus, who was on a rampage to find Ben. He escaped from Aggregor and tells Ben how he ended up captured alongside four other aliens in a plot to permanently absorb their powers. Galapagus ended up telling Ben how he, Bivalvan, Andreas, Ra'ad, and P'andor escaped from Aggregor when Magister Prior Ghilhil answered the distress call and did an inspection which ended with Magister Prior Ghilhil getting knocked out by Aggregor. Though the aliens escaped from Aggregor's spaceship, they crash-landed on Earth. After Ben's Ultimatrix scans Galapagus' DNA, he arranges for the Plumbers to get Galapagus back to his home planet. Unfortunately for Galapagus, Aggregor was posing as a Plumber.

star 8.42
262 votes
Directors: Butch Lukic
Writers: Charlotte Fullerton
Basic Training

#5 - Basic Training

Season 2 - Episode 8 - Aired Apr 1, 2011

Ben, Gwen, and Kevin are summoned to a Plumbers' Academy to go under training that is supervised by Magister Hulka.

star 8.35
208 votes
Catch a Falling Star

#6 - Catch a Falling Star

Season 2 - Episode 27 - Aired Feb 25, 2012

Jennifer Nocturne is recaptured by Captain Nemesis aka Overlord.

star 8.24
90 votes
Eye of the Beholder

#7 - Eye of the Beholder

Season 2 - Episode 2 - Aired Feb 11, 2011

Ben, Julie and the rest of the heroic crew embark on a dangerous journey that could cost them all their lives in an effort to achieve the safe return of Ship and his former owner Baz-L.

star 8.14
135 votes
The Creature from Beyond

#8 - The Creature from Beyond

Season 2 - Episode 7 - Aired Mar 25, 2011

The Forever Knights unleash an evil force mistaken for an ancient weapon.

star 8.12
155 votes
The Forge Of Creation

#9 - The Forge Of Creation

Season 1 - Episode 16 - Aired Nov 12, 2010

Azmuth is upset with Ben, Gwen, and Kevin for letting Aggregor get all the pieces of the Map of Infinity. Ben resolves to become Alien X to get Bellicus and Serena to cooperate. When this fails, Paradox arrives and changes Alien X back to Ben. After a brief argument, Paradox and Azmuth explain that the Forge of Creation is where all Celestialsapiens (Alien X's race) are born, and Aggregor hopes to absorb the powers of a newborn Celestialsapien and become all-powerful. Paradox takes them to the Forge of Creation, where an accident pulls Ben's ten-year-old self out of the timestream. After a few difficulties, past-Ben teams up with his future self to stop Aggregor. As they make their way through the Forge, they discover many Celestialsapiens in debate with themselves, and eventually a Celestialsapien egg. Aggregor reaches the egg at the same time the group does and takes everyone out with ease. In a last-ditch effort, Kevin absorbs energy from present-Ben's Ultimatrix, but the process drives him insane. He now looks like his old self but has the new aliens instead of the old ones. Kevin easily defeats Aggregor before absorbing his stolen power and attempting to kill him only to be met with opposition from Gwen and both Bens. Past-Ben manages to get through to Kevin, who spares Aggregor's life before flying away, claiming he won't be so merciful tomorrow. Paradox arrives at that moment to take them home before the other Celestialsapiens wake up and return past-Ben to his own time period. Paradox claims that past-Ben will dismiss the entire experience as a dream while present-day Ben resolves to stop Kevin.

star 8.10
236 votes
Directors: Dan Riba
Writers: Dwayne McDuffie
Greetings from Techadon

#10 - Greetings from Techadon

Season 2 - Episode 15 - Aired Sep 30, 2011

Techadon robots go after Ben on orders from Vulkanus

star 8.03
177 votes
Nor Iron Bars a Cage

#11 - Nor Iron Bars a Cage

Season 1 - Episode 17 - Aired Nov 19, 2010

With Kevin having absorbed Ben's aliens and become insane once again, Ben and Gwen have to go to the null void prison in an attempt to stop Kevin from destroying all the people there. We learn more about how Kevin got his material absorbing powers. In the end Ben thinks Kevin should be put down.

star 8.03
105 votes
Directors: Dan Riba
Writers: Dwayne McDuffie
The Flame Keeper's Circle

#12 - The Flame Keeper's Circle

Season 2 - Episode 16 - Aired Oct 7, 2011

Julie joins a cult that worships Vilgax

star 8.02
114 votes
It's Not Easy Being Gwen

#13 - It's Not Easy Being Gwen

Season 2 - Episode 9 - Aired Apr 8, 2011

Gwen has always been a multi-tasker, trying to juggle school, hobbies, friends and her work as a hero, waking up early and going to sleep late. But Gwen's already packed day is about to get worse when Dr. Animo attacks with an army of giant frogs and Gwen is forced to make a hard choice.

star 8.01
122 votes
The Purge

#14 - The Purge

Season 2 - Episode 13 - Aired Sep 16, 2011

With the help of The Forever Knights, Old George starts a war against all aliens on Earth.

star 7.98
123 votes
The Widening Gyre

#15 - The Widening Gyre

Season 2 - Episode 20 - Aired Nov 4, 2011

The gang looks into the Pacific Garbage Vortex at the request of the government.

star 7.90
98 votes
Prisoner #775 is Missing

#16 - Prisoner #775 is Missing

Season 2 - Episode 12 - Aired Apr 29, 2011

The secrets of Area 51 are revealed to Ben Tennyson by Colonel Rosum after Old George infiltrates Area 51. (ChamAilen and Ultimate Wildmutt first appears in this episode).

star 7.89
152 votes
The Enemy of My Frenemy

#17 - The Enemy of My Frenemy

Season 2 - Episode 25 - Aired Feb 11, 2012

Gwenand the gang revisit Legerdomain in hopes of rescuing Charmcaster.

star 7.85
150 votes
Hero Time

#18 - Hero Time

Season 1 - Episode 9 - Aired Jun 18, 2010

Ben meets his favorite superhero idol Captain Nemesis when he shows up to save actress Jennifer Nocturne, however Captain Nemesis is displeased when Ben gets kissed by the actress instead of him. Captain Nemesis' assistant, Simons meets up with Will Harangue about staging an event that will put Captain Nemesis back on the front page of each magazine. When Ben wins, The Captain goes to extreme lengths to prove everyone that he is the best superhero of all time. He captures Julie and Jennifer and Ben tries to call Julie to go to Mr. Smoothy's he gets a message from Captain Nemesis telling Ben to try and save her. Ben goes to rescue Julie and Jennifer by going ultimate Humongosaur and uses goop to rescue Julie. Kevin and Gwen rescue Jennifer and Jennifer loves Kevin. Ben defeats Captain Nemesis with Water Hazard and Captain Nemesis gets arrested. But when Jennifer falls in love with Kevin, Gwen threatens her to get her away from Kevin.

star 7.84
251 votes
Directors: Matt Youngberg
Writers: Steven Barnes
Couples Retreat

#19 - Couples Retreat

Season 2 - Episode 26 - Aired Feb 18, 2012

Charmcaster and Darkstar team up to destroy Ben, Gwen and Kevin.

star 7.81
172 votes
Inspector 13

#20 - Inspector 13

Season 2 - Episode 24 - Aired Feb 4, 2012

A mysterious weapon master from Techadon visits Earth and wants the Ultimatrix.

star 7.81
144 votes
Fused

#21 - Fused

Season 1 - Episode 8 - Aired Jun 11, 2010

After ambushing Ben at his house, Ra'ad (one of the aliens captured by Aggregor) blames him for letting Aggregor recapture the other four aliens through the Ultimatrix. While trying to resist being scanned by the Ultimatrix with his electric powers, Ra'ad causes it to malfunction, and ends up deactivating it while both his and Ben consciousnesses trapped within his body. Despite Ra'ad's protests, Gwen and Kevin reactivate the Ultimatrix, and separate Ben from the alien. But in doing so, they alert Aggregor to their location. Ra'ad flees, leaving the others to be wiped out by the Osmosian. After Kevin scolds Ra'ad for his cowardice, the alien decides to sacrifice himself to save Ben, and is recaptured by Aggregor in the process. After the battle, Ben swears that he will do whatever it takes to save the captured aliens.

star 7.80
259 votes
Directors: Dan Riba
Writers: Ernie Altbacker
Moonstruck

#22 - Moonstruck

Season 2 - Episode 11 - Aired Apr 22, 2011

The history of Max and Verdona Tennyson in flashbacks.

star 7.79
125 votes
Video Games

#23 - Video Games

Season 1 - Episode 4 - Aired May 14, 2010

After defeating Ssserpent with Fourarms, Ben's celebrity status lands him in a starring role in a video game. The developers ask him to show off all his aliens' different moves so they can be implemented into the game. In reality, TV reporter Will Harangue has been using the video game to build a giant spider-like robot that knows all of Ben's aliens' moves from when he openly showed them. After being defeated twice by Harangue's robot, he challenges Ben to a final showdown on live TV. After realizing how Harangue's robot can predict his aliens' moves, Ben uses Humongousaur with sumo slammer moves to fight it. He damages it until it has lost control, but its still shooting randomly. Ben then turns into Nanomech which was the only alien with moves that were not installed into the robot, Ben is able to defeat it from the inside.

star 7.77
294 votes
Directors: Dan Riba
Writers: Eugene Son
Revenge of the Swarm

#24 - Revenge of the Swarm

Season 2 - Episode 6 - Aired Mar 18, 2011

Victor Validus resurfaces and attacks Ben at night. Elena Validus and the nanochips return.

star 7.73
186 votes
Absolute Power (1)

#25 - Absolute Power (1)

Season 1 - Episode 19 - Aired Dec 10, 2010

When Ben and Gwen are faced with an unexpected enemy, Gwen turns to Darkstar for help.

star 7.72
192 votes
Directors: Dan Riba
Writers: Charlotte Fullerton