He is portrayed as a journalist and talk show host, usually living in Gotham City, who gains the ability to transform into the superhuman the Creeper (and vice versa) thanks to experimental science developed by Dr. Yatz.

Originally, Ryder's transformation into the Creeper involved activating a device that granted superhuman abilities while also causing his face to be covered in yellow make-up, his hair to be concealed by a green wig, and his clothing to be instantly replaced by a yellow and red costume with green trunks and a fur-like cape; as the Creeper, Ryder then shifted his voice tone and acted chaotically to intimidate foes and protect his identity.

Starting in 1987, it was said Ryder suffered an actual slight change in personality when he became the Creeper, as the device not only empowered him and dressed him in a costume but also altered his brain chemistry.

In the New 52 continuity, a short-lived incarnation of the Creeper was a villain, not a hero, a malicious oni (demon) who inhabited human hosts to create chaos.

[5] The Creeper repeatedly fought a chameleonic villain called Proteus, whose true identity was revealed just before his violent death in the final issue.

After the origin was reprinted in Detective Comics #443 (November 1974), Jack Ryder was shown working as a news anchor on Gotham City television in issue #445 (March 1975).

The story, which featured a character intended to emulate Peanuts creator Charles M. Schulz, began with the Creeper being mistakenly blamed for a crime the Joker committed due to their similar appearances (specifically, green hair and a maniacal laugh).

2) #18 (1987), in a story presented by Andrew Helfer and Keith Giffen, the Creeper was given a new origin and it was now said Ryder's behavior while in costume was not simply an act.

Taking place outside of mainstream DC canon, this story featured Judith and Madeline Benoir, twin sisters living Paris in the 1920s.

Jack Ryder was reintroduced in a follow-up comic DCU: Brave New World (2006), in a short story written by Steve Niles and drawn by Justiniano.

The story depicted Ryder as a former journalist who now hosted a talk show named You Are Wrong, where he often attempted to expose corruption and provide commentary on news events.

2) (October 2006 – March 2007), also written by Niles and drawn by Justiniano, featured a flashback story revealing the Creeper's newly revised origin, connecting him to the Joker.

The idea that Ryder has a mental illness before ever becoming the Creeper is eliminated; this alter ego's personality is a result of experimental science affecting his body, mixed with the Joker's signature madness-inducing chemical weapons.

The same story quickly became notorious among readers for many internal continuity errors and unexplained contradictions with the accepted DC Comics canon, making its place there questionable at best.

[9] The issue portrayed the Creeper as an oni who "justifies cruel temper tantrums under the guise of spreading chaos" and inhabits numerous human hosts, including Jack Ryder.

Jack Ryder and the Creeper appeared again afterward, now once again depicted as a man who becomes a yellow-skinned superhuman due to scientific experimentation rather than demonic possession.

Brane reveals that CIA contacts have asked him to help find Dr. Yatz, a scientist captured by gangster Angel Devlin.

Following the Crisis on Infinite Earths continuity reboot, Jack Ryder is depicted as a newspaper journalist working for the Herald Examiner.

He is shot and left to die while investigating a case, but scientist Emil Yatz rescues him and gives him powers using his experimental "inorganic matter transference" technology.

This activates another device hidden underneath his skin that would rearrange molecules, immediately replacing Ryder's clothing with the Creeper's costume, yellow make-up, green wig, and red, fur-like cape.

This also activates a chemical Dr. Yatz had injected inside Ryder, thus granting him enhanced strength, stamina, durability, speed, agility, reflexes, healing, and senses.

As a result, each time he transforms again, this device not only restores Ryder's powers, but it alters his brain chemistry to mimic a distinct personality.

The Creeper has immense strength, stamina, durability, speed, agility, reflexes, and healing, as well as hyper-keen senses, pain-inducing laughs, and fearful presence.

[22] In a possible future in the 853rd century depicted in DC One Million, an entity from the planet IAI called RYDR senses a disturbance that threatens to unravel reality and transforms into the Creeper to avert it.

Additionally, he resents Bruce Wayne after his co-anchor Adalyn Stern becomes the new Scarecrow due to a traumatic childhood experience she had with Batman.