Part of Cheshire's gang who perform the STAR Labs heist in "Triptych," The Mist is a teenage metahuman with the power to change her body into fog. She is later revealed to have been mind-controlled into working for Stagg Industries. A female villain called The Mist was the self-proclaimed arch-enemy of Jack Knight - the protagonist of the 1994 Starman series. Daughter of the original Mist, she replicated the process that gave her father his powers and dedicated herself to Jack Knight's destruction after he killed her brother and drove her father insane.
After making her escape from STAR Labs in "Triptych", Cheshire has her bullet wound treated by a man named Dr. Moon, who apparently acts as an on-call doctor for supervillains in need of healing. First appearing in Batman #240, Dr. Moon was a former brain surgeon who started selling his services to the underworld in order to finance his illegal experiments. Over the years, Dr. Moon has been employed by The Joker, the Suicide Squad and Black Lightning's arch-enemy Tobias Whale.
Eagle-eyed fans may recognize Galet Dasim - one of the aliens Lobo tells to get out of his way in the episode "Home Fires" - as the prosecutor who oversaw the trial of the Justice League members accused of attacking the plant Rimbor in Young Justice: Invasion. While the character of Galet Dasim is unique to the reality of Young Justice, his name and character design are close to that of the Green Lantern Malet Dasim. A lawyer before he was found worthy of joining the Green Lantern Corps, Malet Dasim frequently oversees the internal legal proceedings whenever a Lantern's actions are brought into question.
Ron Evers is one of Victor Stone's teammates, who says he would like to date Black Canary if he had superpowers. In the comics, Ron Evers was a friend of Victor Stone, who began investigating STAR Labs after Victor mysteriously disappeared following his transformation into Cyborg. Seeing what his friend had been turned into and assuming the worst, Ron attempted to blow up the lab only to injure himself and be transformed into a cybernetic super soldier for the US Government himself. Though Victor would later see Ron freedl, their friendship never recovered and Ron went on to become a minister who led a religious sect with strong anti-technology beliefs.
Sebastian Cardona is another one of Victor Stone's teammates, who says he would like to date Wonder Woman if he suddenly found himself with superpowers. In the comics, Sebastian Cardona was a star football player for the chief rival of Victor Stone's high school. The two would meet years later after Victor Stone had become Cyborg and became good friends.
The equipment manager for Victor Stone's football team, Cisco is mocked when he says that he'd rather date Zatanna over Black Canary or Wonder Woman, when trying to join in the locker room talk. Though his last name is never mentioned, it's clear that this Cisco is Cisco Ramon, a.k.a. the superhero Vibe. Though he was a member of the Justice League in the 1980s, Cisco is probably better known and better loved today as the engineering genius behind Barry Allen's super-suit and countless anti-metahuman weapons on The Flash series on The CW.