The DEO or the Department of Extranormal Operations first appeared in Batman #550 (1998), created by Dan Curtis Johnson and J. H. Williams III. Its Executive Director was the former Infinity, Inc. villain, Mr. Bones. Its directive is to monitor anyone with extra-normal abilities and prevent any threat to the general public those beings could pose. In the Comics they handle all superpowered beings, not just the extraterrestrial variety. Like any government agency there have been members and divisions that pushed the legally of a government operated organization.
There have been several characters in DC Comics called Toyman. This first is Winslow Schott. He was created by Don Cameron and Ed Dobrotka. He was introduced in Action Comics #64 (September 1943). Pre-Crisis he was a mad toymaker who became increasingly unstable. Post-Crisis he was a British Toymaker who blamed LexCorp and Lex Luthor for his termination from the toy company he worked for.
The second Toyman in DC Comics was Jack Nimball. The doll left at Winn’s desk bears a resemblance to that version. Nimball was created by Cary Bates and Curt Swan. He debuted in Action Comics #432 (February, 1974). The Nimball Toyman was the version used in the Challenge of the Super Friends (1978) TV Show.
The third Toyman was Hiro Okamura, a Japanese teenaged mechanical genius. He was created by Jeph Loeb and Ed McGuinness. He first appeared in Superman (vol. 2) #177 (February 2002). He showed up coming after Metallo, claiming Metallo’s body was based on his grandfather’s technology. He later became Superman and Batman’s ally. Hiro is the New 52 version called Toymaster.
The fourth is Toyman robot also referred to as Toyboy. He was created by Geoff Johns, Kurt Busiek, and Pete Woods. He was introduced in Action Comics #837 (May 2006). This version was based on the Toyman seen in Superman: The Animated Series. Toyboy was one of Toyman’s, Winslow Schott’s, robotic minions. The toy doll in Schott Sr.’s cell is an allusion to this version of the character too.
The first Turtle was created by Gardner Fox and Martin Naydel. He debuted in All-Flash #21 (December, 1945). His nemesis was the Golden Age Flash, Jay Garrick. He was slow and methodical planner. He returned in the 1980’s as a villain for Wally West. He was later given the power of stealing speed and slowing everything around him down. The Naydel Library was a nod to one of the creators of the First Turtle.
The second Turtle also known as Turtle Man was created by Robert Kanigher and Carmine Infantino. He first appeared in Showcase #4 (October, 1956). He was one of the first gimmicked villains for the Silver Age Flash, Barry Allen. He used gadgets based on slowness. He later became the henchman of the first Turtle.
Midway City was mentioned in this episode. That is the home base of the Silver Age Hawkman and Hawkwoman. It also is home to the Doom Patrol as well. Markovia was also mentioned, it is the home of Prince Brion Markov AKA Geo-Force, and he was a member of Batman’s Outsiders.
John Diggle was created for the Arrow Show by Andrew Kreisberg and Marc Guggenheim in 2012. He was introduced in the DC New 52 Comics universe in Green Arrow Vol. 5 #24 (December, 2013). John and his brother Andy were named after Andy Diggle who wrote Green Arrow: Year One (2007). It seems that his codename in Season 4 is Spartan.
Rip Hunter was created in Showcase #20 (May 1959) by Jack Miller and Ruben Moreira. Richard “Rip” Hunter was a time traveling hero who was called the Time Master. His original run was 1961 to 1965. He disappeared for a while, but returned in 1983 with a group referred to as the Forgotten Heroes. That team included the amphibian Dolphin, the spelunker, Cave Carson, Rick Flag of the original Suicide Squad, Dane Dorrance of the See Devils aquatic adventuring team, Congorilla, Immortal Man (Vandal Savage’s nemesis), and The Animal Man. Rip, Post-Crisis, became the go to character for Time Travel. Since he has been the son of Booster Gold, and he has been a member of the Linear Men.
Waverider, the ship, is named after a time traveling superhero with the same name, who tried to prevent one superhero going bad and taking over the world. Waverider was created by Archie Goodwin and Dan Jurgens. He first appeared in Armageddon 2001 #1 (May 1991). Waverider went through various revisions after his initial appearance in Armageddon 2001.
There are three different characters that have used the name Chronos in the DC Comics universes. The first Chronos was David Clinton created by Gardner Fox and Gil Kane. He debuted in The Atom #3 (1962). He was a petty thief and nemesis of the Silver Age Atom, Ray Palmer. He went from a character about timing to having time related gadgets and powers.
The second was Gabriel Walker. He was first introduced in Chronos #1 (March 1998) and created by John Francis Moore and Paul Guinan. After Clinton’s death Walker gained possession of all of Clinton’s research. This version was both a hero and a criminal depending on the various circumstances. Then there was a Lady Chronos, she was the adversary of the Atom, Ryan Choi.