The BEST Episodes of Ben 10: Ultimate Alien

Every episode ever - ranked by fan votes!

Last Updated: Nov 5, 2019

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

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 8.55
53 votes
Solitary Alignment

#2 - Solitary Alignment

Season 2 - Episode 23

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

star 8.40
22 votes
Prisoner #775 is Missing

#3 - Prisoner #775 is Missing

Season 2 - Episode 12

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 8.38
29 votes

#4 - Moonstruck

Season 2 - Episode 11

The history of Max and Verdona Tennyson in flashbacks.

star 8.38
29 votes
Greetings From Techadon

#5 - Greetings From Techadon

Season 2 - Episode 15

Techadon robots go after Ben on orders from Vulkanus

star 8.33
27 votes
Map of Infinity

#6 - Map of Infinity

Season 1 - Episode 11

With his new powers, Aggregor easily defeats Ben and his friends. Azmuth tells Ben that Aggregor intends to steal the Map of Infinity, a complete map of the entire universe. With it, he'll be able to find the Forge of Creation, the birthplace of the universe. He further explains that Aggregor stole the five aliens' powers to protect him from the traps guarding the map, which is split into four pieces. In order to keep him from assembling the map, the team tries to take one of the pieces first. Aggregor, however, simply follows them and steals it after they disable the traps for him.

star 8.31
54 votes
Directors: Matt Youngberg
Writers: Dwayne McDuffie
Revenge of the Swarm

#7 - Revenge of the Swarm

Season 2 - Episode 6

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

star 8.26
35 votes
The Ultimate Sacrifice

#8 - The Ultimate Sacrifice

Season 2 - Episode 19

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

star 8.21
33 votes
Escape From Aggregor

#9 - Escape From Aggregor

Season 1 - Episode 5

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 8.19
57 votes
Directors: Butch Lukic
Writers: Charlotte Fullerton
The Perfect Girlfriend

#10 - The Perfect Girlfriend

Season 2 - Episode 18

The Perfect Girlfriend

star 8.18
23 votes
Eye of the Beholder

#11 - Eye of the Beholder

Season 2 - Episode 2

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 8.18
39 votes
It's Not Easy Being Gwen

#12 - It's Not Easy Being Gwen

Season 2 - Episode 9

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 8.16
25 votes
Girl Trouble

#13 - Girl Trouble

Season 2 - Episode 5

Gwen is excited by the prospect of her cousin Sunny paying the team a visit while dealing with the Robots of Dimension 12. But her excitement quickly turns into trepidation when it is uncovered that her cousin is not all that she appears and has some particularly sinister intentions.

star 8.14
35 votes
The Flame Keeper's Circle

#14 - The Flame Keeper's Circle

Season 2 - Episode 16

Julie joins a cult that worships Vilgax

star 8.12
18 votes
The Enemy of My Frenemy

#15 - The Enemy of My Frenemy

Season 2 - Episode 25

Gwenand the gang revisit Legerdomain in hopes of rescuing Charmcaster.

star 8.12
26 votes
Nor Iron Bars a Cage

#16 - Nor Iron Bars a Cage

Season 1 - Episode 17

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 8.11
37 votes
Directors: Dan Riba
Writers: Dwayne McDuffie
Absolute Power (2)

#17 - Absolute Power (2)

Season 1 - Episode 20

Ben and Gwen are forced to go to Darkstar for help when they come across their most deadly, most unexpected foe yet.

star 8.08
37 votes
Directors: Dan Riba
Writers: Charlotte Fullerton

#18 - Perplexahedron

Season 1 - Episode 15

With the fourth piece of the Map of Infinity almost in Aggregor's clutches, the gang chase him through the artificial planetoid known as Perplexahedron.

star 8.08
52 votes
Directors: Matt Youngberg
Writers: Brian Swenlin
Andreas' Fault

#19 - Andreas' Fault

Season 1 - Episode 7

When Ben, Kevin, and Gwen investigate an odd string of thefts by the Forever Knights, they learn that Argit is using Andreas (one of the aliens being hunted by Aggregor) to frighten them into making him their leader. Argit's plans go bad when the Forever Knights eventually revolt, and throw him into a dungeon with Ben and the others. When they discover that the Knights plan to execute Andreas, they break out and save him. But when a Forever Knight sets a bomb that would level the entire castle, Andreas sacrifices himself to absorb the force of the explosion. Although Ben and company believed him to be dead, Andreas survived the explosion. Unfortunately, the endeavor of stopping the bomb made him too weak to resist Aggregor as he recaptures him.

star 8.07
48 votes
Directors: Dan Riba
Writers: Ernie Altbacker
Hit 'Em Where They Live

#20 - Hit 'Em Where They Live

Season 1 - Episode 3

After Jimmy Jones reveals Ben's identity, some of his enemies (such as Zombozo, Rojo, Charmcaster, Vulkanus, and Sevenseven) team up to try to attack his family. Now Ben and his friends have to protect them no matter what.

star 8.06
71 votes
Directors: Matt Youngberg
Writers: Len Wein
Video Games

#21 - Video Games

Season 1 - Episode 4

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 8.03
64 votes
Directors: Dan Riba
Writers: Eugene Son
The Purge

#22 - The Purge

Season 2 - Episode 13

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

star 8.00
27 votes
Catch a Falling Star

#23 - Catch a Falling Star

Season 2 - Episode 27

Jennifer Nocturne is recaptured by Captain Nemesis aka Overlord.

star 8.00
21 votes
Basic Training

#24 - Basic Training

Season 2 - Episode 8

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

star 7.99
31 votes
Absolute Power (1)

#25 - Absolute Power (1)

Season 1 - Episode 19

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

star 7.98
41 votes
Directors: Dan Riba
Writers: Charlotte Fullerton