Casey Jones

Arnold Casey Jones Jr. aka Casey Jones is a hockey-masked vigilante who fights crime at night.

History
Contrary to the 1987 series, Casey Jones becomes a more regularly recurring character in the 2003 TV series. He speaks in a Brooklyn accent. This incarnation's personality is on par with Raphael's. As in the Mirage comics, Raphael first meets Casey while the vigilante tries to stop a mugging. Raphael stopped him from seriously injuring a gang of Purple Dragons, seeing a lot of himself in Casey, Raphael tries to reason with him and prevent him from letting his anger get the best of him. The two fought with each other, but were brought back to their senses by their common enemy. Though initially uninterested in what he had to say, Casey eventually bonds with Raphael. Casey was at that occasion formally (re-)introduced to the Turtles; after that, they became close friends and allies.

Casey's backstory is fleshed out over the course of the series. Casey's hatred of crime is rooted in this incarnation in his childhood. While Casey was still a kid, his father Arnold Casey Jones, Sr. refused to pay protection money to the Purple Dragons. His father's shop was burned down as a result, and a teenage Hun threatened Casey to tell his father to pay up next time. (Fallen Angel) Despite being threatened not to, Jones, Sr. subsequently went to the police, but with no success; it is implied that the Purple Dragons later killed him for trying to turn them in. For this reason, Casey cherishes a special aversion to Hun. Dragons Rising features a flashback of Casey's father telling him the importance of doing "the right thing." In the present, Casey relates this to Hun, who replies that he "was dead wrong!" As a result, Casey developed a deep hatred for crime, the Purple Dragons in particular, and vowed to get revenge.

Arnold Casey Jones, Jr. — first name rarely spoken (except by his mother) — it is revealed in "The Lesson" that he first met the Turtles as a kid, (though neither the Turtles nor Casey himself are aware of this fact). During a trip to the surface, the young Turtles witness bullies picking on young "Arnie." Disguising themselves as a human child they tried to teach him ninjutsu, however, their unique perspectives and attitudes lead to more trouble than not and they failed. However, in the end their lessons inspired him to stand up to the bullies in order to save a friend, and (in a bit of foreshadowing) using one of their own hockey sticks to defeat them and proclaiming they were no match for "Arnold Casey Jones!".

As he grew older, Casey became a vigilante and started hunting down crooks — particularly Purple Dragons — in the streets. Incidentally, fate brought him across the path of Raphael once again. Casey Jones would help the Turtles out with various operations and the Turtles would return the favor.

Despite his lack of intelligence and apparent incompetence, he was early on in the series referred to by Hun as "Our (the Purple Dragon's) greatest enemy," and a fighting tournament was held to see which Dragon would have the honor of killing him, indicating how serious a threat the criminal underworld views him as.

In the series, in contrast to earlier representations, Casey has a good heart and is a loyal friend., but is easily enraged and occasionally bumbling. He loves motorcycles. In a symbolic way, he sees the Turtles as the little brothers he never had. As such, he often comes to their aid against The Utrom Shredder, the Foot Clan or other enemies. His main catchphrase as in the Mirage comics is the battle cry "Goongala!" "The Lesson" reveals Casey's modern-day battlecry originated from a young Michelangelo, who taught him to shout "Goro Goro Sama!" (literally, "Mr. Thunder"), which Casey ultimately garbled into "Goongala!".

Through the Turtles, early on he met April O'Neil, for whom he quickly developed a romantic attraction. However, their conflicting personalities lead to frequent arguments at first. Over time, a serious relationship develops. Casey is actually "only" a street fighter and not a true martial artist, but he is a strong and skilled fighter and friend of the Turtles, who knows how to defend himself well. Also in some episodes Casey's family is presented in more detail, especially his mother and his cousin Sid.

Trivia

 * In the 13th episode of season 3, "The Lesson", Casey's modern-day battlecry originated from Michelangelo, who taught him to shout "Goro Goro Sama!" (literally, "Mr. Thunder"), which Casey ultimately garbled into "Goongala!"
 * Casey's favorite food has been stated to be Italian, Mexican, and pretzels.
 * Casey's favorite color is green.
 * Casey acquired some basic martial arts skills as an unwitting stooge of Master Khan during the year the Turtles spent in the future. However, he still prefers to go into combat with his battering equipment.