Rath is the Omnitrix's DNA sample of an Appoplexian from the planet Appoplexia.
Rath is about nine feet tall. He resembles an orange and white bipedal tiger with one black claw coming out of each wrist and no tail. He is also muscular and has green eyes and black stripes on his shoulders, head, legs and upper body as well as a white jaw, neck, chest, stomach, hands and feet. He wears black and green pants with white markings and 'luchador' gloves. He wears the Omnitrix symbol on his chest.
Rath almost always speaks in third person. Sometimes, when he becomes extremely angry, he mixes up metaphors (such as "a man's food is his castle" or "you just bit off an eye that's bigger than your stomach can chew"). He is self-aware that they do not make sense, but still continues to use them anyway.
Rath's muscle-over-brains mindset makes him needlessly argue with everyone around him. He even shouts at inanimate objects, like a hole he made in the ground, a stolen spaceship, gravity, water, fire, the Omnitrix and Ultimatrix for their malfunctions, the Proto-Tool's laser pointer, a giant ball of yarn, and a paper bag on his head, arguments of which were ridiculous and that occasionally lead him to harm both himself and others. His big mouth often gets Rath and his teammates into trouble, such as when Kevin tried to reach an agreement with Vulkanus, Rath began mocking the latter's defeats from them and called him "baby man", resulting in the negotiation downgrading into a fight.
When Rath is angry at someone or something, he usually yells a sentence starting with, "Let me tell ya something" followed by the full name of the person, calling Kevin by his, or their position, labeling Khyber as "self-proclaimed greatest huntsman in the galaxy".
Rath is very fearless to the point of recklessness, as he didn't hesitate to literally jump down Jarett's throat to rescue the Tiffin or about firing the Vreedle Brothers out into space after they blasted him and his tray of food. Rath also does not make empty threats, as shown after saving the Tiffin and threatening to mutilate Jarett with rearrangement of his organs into a sweater if he started a war with the Lewodans, his low growl hinted he meant it. He also once outright stated he intended to hit Rojo in the head during a train robbery. Ben even agreed with Gwen's premonition that Rath would do something unthinkable if he ever went after J.T. and Cash upon learning about them taking credit for his heroics.
Rath has a lot of pride in his capabilities and himself, expressing bluntness or anger instead of gratitude when Gwen and Rook saved him on several occasions Similarly, he denied needing enhancements from Skurd against Exo-Skull.
Over time, Ben has gained slight control of himself as Rath. He once lowered his voice when talking to Gwen on the phone, even though he had two Forever Knights at his ferocious mercy, and mildly called her unempathetic response "harsh".
Because of Rath's extremely low intellect, Kevin can't help but mock or make fun of him.
Despite the fact that Rath is supposed to know nothing but anger and fighting, he is shown to be friendly towards the Tiffin, though not at first.
Rath does not have a very good sense of humor, as he gets mad whenever someone mistakes him for a "kitty".
Powers and Abilities
Rath possesses enhanced strength and agility, enabling him to jump great distances and lift objects heavier than himself. This was shown by how he was able to easily dismember the Forever Knights' paramilitary tank via brute force and toss the still extremely large pieces around (with one hand and later with two for the tank's body) with minimal to no effort. Rath's strength also gives him an advantage in combat, allowing him to power his way through many opponents and smash through tough defenses.
Rath's unbridled aggression gives him a psychological edge in combat. There are very few things that Rath fears and many opponents find it extremely difficult to beat him if he is fully enraged.
Rath possesses a large, retractable black claw on each wrist. This claw can be used to stab and slice opponents or to create a shock wave when stabbed into the ground. Whenever Rath gets determined or angry, his claws seem to grow larger.
Rath's also has a very strong bite force, as he was able to easily shatter SevenSeven's blade with his sharp teeth.
Rath is extremely durable, being able to take a point-blank laser blast with no apparent effect and survive a free fall from several hundred feet in the air with only a bit of dizziness as a result. He can also run very fast, and run on walls.
Rath can also release a loud roar, although is seems to be more of an intimidation tactic rather than an offensive feature.
Even though he is not one of the smartest of Ben's aliens, Rath can perform fighting moves with expert execution, as seen when he used wrestling moves to defeat Manny and a Techadon robot.
Rath's brain is hardwired for aggression and as such, Rath's main weakness is his lack of intelligence and highly aggressive temperament. This causes Rath to become easily distracted and difficult to stop once he starts fighting. He is also not quite adept for diplomatic approaches, particularly negotiations, and can make bad or difficult situations worse.
Rath's apparent lack of intelligence also often convinces him to needlessly argue with inanimate objects.
Rath is scared of water, like most actual cats, but unlike actual tigers.
Rath can be subdued by the Hephestan Neuro Grip.
Rath can be lifted and thrown by species with as much or more strength than a Zaroffian.
Rath has very sensitive hearing, which makes him vulnerable to loud piercing sounds, such as a certain sonic frequency signal.
Being feline-based, Rath can be controlled by people that have the ability to control cats, like Nyancy Chan. He can also be easily distracted by a laser pointer.