From the classic Ben 10 to Ben 10: Omniverse, the original canon of Ben 10 featured an extensive roster of aliens for the titular hero to transform into. With an array of creatures that have different strengths and powers, many fans will agree that each one has offered something unique to the show.
Question is, if fans had to choose, which one would they say is the best? All these years later (and not including characters in the reboot), which aliens have managed to leave a great impression?
Goop
![10 Best Alien Forms From The Ben 10 Franchise, Ranked](https://static1.srcdn.com/wordpress/wp-content/uploads/2021/09/Ben-Tennyson-in-his-Goop-form-in-Ben-10-Alien-Force.jpg)
A rather bizarre alien since Ben not only controls Goop’s slime-like body but also has a gravity manipulation device that allows Goop to operate. Made entirely out of slime, Goop can traverse through small crevices, is nearly indestructible, and can form any shape, thanks to its natural polymorphic state (combined with the device).
The design of Goop is much like the name Ben chose for it: simple yet effective. It’s a vibrant almost neon green being of slime, with bright eyes and a gurgly high-pitched sound (and voiced by Dee Bradley Baker). The animators clearly have a lot of fun creating all kinds of forms for Goop to take, besides his default humanoid one.
Ripjaws
![Ben Tennyson in his Ripjaws form in Ben 10](https://static1.srcdn.com/wordpress/wp-content/uploads/2021/09/Ben-Tennyson-in-his-Ripjaws-form-in-Ben-10.jpg)
Mixing a human with an angler fish, Ripjaws is an aquatic alien that sadly did not get used very much in the original Ben 10 series. Whenever Ben did use Ripjaws, he was a standout due to his intense speeds in water, enhanced strength, and razor-sharp jaws that can tear through metals (both Earth and alien-like).
This alien has a design reminiscent of the Gillman from The Creature From The Black Lagoon. As such, Ripjaws was not exclusive to water: he has the ability to swap between a fishtail and legs, allowing him to deal damage on land. However, he can only stay on land for a limited time before he can hydrate.
Diamondhead
![Ben, Gwen, and Grandpa Max marveling at Diamondhead in Ben 10](https://static1.srcdn.com/wordpress/wp-content/uploads/2021/09/Ben-Gwen-and-Grandpa-Max-marveling-at-Diamondhead-in-Ben-10.jpg)
One of Ben’s most used aliens in the original series, Diamondhead is a massive being made out of nearly indestructible diamond-like crystals. He featured full control over these crystals, able to form barriers, weapons, crystalline projectiles, and other constructs from his body.
That’s not all: Diamondhead was capable of absorbing energy, reflecting and refracting energy-based attacks, and was immune to heat, cold, space, and so much more. The crystalline humanoid design was another simple yet effective one, looking akin to something out of both fantasy and sci-fi stories.
Upgrade
![Ben in his Upgrade form in Heroes United](https://static1.srcdn.com/wordpress/wp-content/uploads/2021/09/Ben-in-his-Upgrade-form-in-Heroes-United.jpg)
This alien is similar to the Klyntar symbiotes from Marvel such as Venom or Carnage. In this form, Ben is a polymorphic organism that can bond with a host. In this case, instead of people, Upgrade bonds with technology to hack or blend into them, and (as the name suggests) upgrade them to become powerful weapons for Ben to use.
Upgrade also sports a circular eye, which can emit optic blasts and beams. In many ways, Upgrade can be an overpowered alien since he can transform a standard piece of tech into a weapon of mass destruction. Fortunately, Ben mainly uses it to hack into areas and take advantage of his polymorphic body.
Heatblast
![Heatblast wielding a fireball in Ben 10](https://static1.srcdn.com/wordpress/wp-content/uploads/2021/09/Heatblast-wielding-a-fireball-in-Ben-10.jpg)
Old school fans will recognize this as Ben’s very first alien he ever transformed into. During the original series run, Heatblast became one of the signature alien forms seen on posters, merchandise, and even the intro. With his lava rock-like skin covering a flame body (combined with the voice of legendary voice actor Steve Blum), it’s easy to see why Heatblast is so beloved.
Heatblast can obviously harness his fire in many ways: he can create flame jets, throw fireballs, absorb fires, and anything that can be thought of. He can also mix his flames with his rocky exterior, allowing him to fly on a hand-made meteor or create bombs with his rocks.
Humungousaur
![Humungousaur fighting a DNAlien in Ben 10: Alien Force](https://static1.srcdn.com/wordpress/wp-content/uploads/2021/09/Humungousaur-fighting-a-DNAlien-in-Ben-10-Alien-Force.jpg)
Not much is needed to be said: Humungousaur is a massive humanoid dinosaur with massive strength that allows him to throw objects or people into near-orbit. Humungousaur can also alter their size, allowing them to grow to anywhere from ten feet tall to sixty feet.
Much like dinosaurs seen in the Jurassic Park/World franchise, Humungousaur features a hard hide and resembles a bipedal mix of a Brachiosaurus and the Tyrannosaurus Rex.
Swampfire
![Swampfire making his first appearance in Ben 10: Alien Force](https://static1.srcdn.com/wordpress/wp-content/uploads/2021/09/Swampfire-making-his-first-appearance-in-Ben-10-Alien-Force.jpg)
Take Heatblast and merge him with Wildvine, the result is the vegetation creature known as Swampfire. Not only is Swampfire a botani-kinetic, which allows him to manipulate plants and other vegetation around him with ease, he also sports pyrokinesis. These two abilities seem like polar opposites but they work well together.
That’s not all. Swampfire can stretch and expand his vine-like limbs seemingly endlessly; he can control and emit methane gas, and can projectile fire spikes from his body. Swampfire is an all-in-one alien that rivals the likes of Swamp Thing and Poison Ivy from the DC universe.
Big Chill
![Big Chill freezing a wall in Ben 10: Alien Force](https://static1.srcdn.com/wordpress/wp-content/uploads/2021/09/Big-Chill-freezing-a-wall-in-Ben-10-Alien-Force.jpg)
One of Ben’s creepier forms is this humanoid moth-like alien known as Big Chill. Not only is Big Chill’s true form creepy on its own, but his wings also fold together to create a cloak and hood for him to blend in. This is somewhat similar to how the Judas Breed stalked humans in the Mimic movies.
As his name hints, Big Chill’s main ability is based on the cold: he has breath that can freeze the densest materials, can freeze with a single touch, and create a beam of cryogenic energy from his mouth. The ability to fly is obvious but Big Chill is also capable of intangibility to phase through solid matter.
Four Arms
![Four Arms charging into battle in Ben 10](https://static1.srcdn.com/wordpress/wp-content/uploads/2021/09/Four-Arms-charging-into-battle-in-Ben-10.jpg)
Resembling the powerful villain, Prince Goro from Mortal Kombat, Four Arms was another go-to form for Ben in the original Ben 10 series. It’s easy to see why as he features the most adaptable form (besides his extra arms since he is essentially a crimson-skinned humanoid).
Four Arms’ abilities are also the most basic but in a good way: he’s incredibly strong and durable. This allows him to take on powerful enemies in hand-to-hand combat; he can create powerful shockwaves by clapping his hands and create powerful tremors by slamming his feet.
XLR8
![Ben Tennyson in his XLR8 form in Ben 10](https://static1.srcdn.com/wordpress/wp-content/uploads/2021/09/Ben-Tennyson-in-his-XLR8-form-in-Ben-10.jpg)
Born with wheel-like orbs on their feet, Kinecelerans are natural-born speedsters. Ben’s own Kineceleran, named XLR8, is one of the most useful alien forms due to his speed (capable of reaching up to five hundred miles per hour within two seconds).
In the Ben 10,000 episode, XLR8’s speed increased as Ben got older and more adept – allowing him to traverse the Earth in seconds. On top of the speed, XLR8 sports razor-sharp claws, he has an accelerated brain, and features a tail he can whip enemies with.