Much like her brother, Tuppence is rash, arrogant, and mostly relies on her strength to win fights. She has little compassion for others. She makes her own rules, and is quick to anger when someone challenges her.
The twins dress and talk very much alike. Tuppence has blonde hair which she keeps in a ponytail and has two lines shaved across her temples. She uses excessive makeup, including purple lipstick, and has multiple earrings, one of which is a safety pin. She wears a white top and a black plaid skirt, held up by red suspenders. She wears boots and torn stockings, and finger-less gloves that reach to her elbows.
By 2016, she has matured quite a bit, and built up muscle. She traded the skirt for black hot pants.
Tommy and Tuppence attempted to rob Gemini Gems in the Central City Mall. Kid Flash and Superboy tried to intervene, but things escalated and the Terror Twins took hostages. The fight eventually moved outside to the car park, where they were surprised to see Flash and Superman had also responded to the commotion. Outnumbered, they fled, pursued by Superman.
Tuppence Terror was captured by Kylstar, and stored in a crystalline prison cell with all captured heroes and villains. After the captured heroes escaped, they contemplated liberating the villains, but decided not to and find their captor first.
Kylstar's Vessel December 1, 23:58UTC
The Justice League, Superboy, Miss Martian's valiant effort against Kylstar convinced him to treat his sentient weapons better. All captives, including Tuppence, were released, and Orb-One explained Kylstar's motives. He was a freedom fighter who was on a mission to stop slavers who destroyed his homeworld. As a sign of his good intentions, he offered to return captives unwilling to help with his fight back to their homeworlds. Those willing to stay were promised good treatment and glorious battle.
The Collector's Ship December 1, 19:01EST
Tuppence, along with all of Kylstar's captives from Earth, were teleported into the Collector's Ship. With the additional reinforcements, the Collector's body was quickly destroyed.
Metropolis December 1, 19:03EST
The body was merely one of many, and the Collector unleashed several additional Coludroids on the assembly. The battle was interrupted when the Collector noticed that the probe he embedded underneath Metropolis was malfunctioning. If nothing was done, Earth would be destroyed. Since the Collector was a preserver and not a destroyer, he agreed to shut off the beam that was slowly shrinking the City. After the assembled heroes convince him of their determination to prevent him from taking the city, he begrudgingly agreed to re-size it back to normal and leave.
Metropolis December 1, 22:03EST
The Collector teleported all Earthlings into the city. The villains were nowhere in sight, and the assembled heroes thought that the Collector had teleported them elsewhere to spite them. Unbeknownst to them, the villains were actually just yards away, mentally shielded by Gorilla Grodd, who informed them they now owed him.
They located Blue Beetle outside El Paso, and attacked him and his friend Impulse. Tuppence intercepted Blue Beetle in mid-air, and held him down with her brother for Icicle to freeze him. It didn't hold, however, and Tuppence was knocked out by a punch from Beetle. The two heroes got away.
The strike team infiltrated the Cave, and Tuppence went after Beast Boy. She surprised him in his room, and knocked him out with one punch. She fitted him with an inhibitor collar and carried him to the Mission Room. In the Mission Room, Impulse thought he could take on Tuppence. She was too durable, however, and he bounced right off her, straight in Tommy's hands, who gave him a collar. Tuppence carried Beast Boy aboard the Manta-Flyer. She was already on board when Blue Beetle, unsuccessfully, tried to escape.
Onslaught oversaw security at a meta-human auction and arena fight held in an abandoned mall. She and her brother were guarding the prisoners before being alerted of intruders. After chaos broke out, she watched as her brother being irritated that they couldn't participated in the battle before spotting Nightwing and Tigress trying to liberate the captives. The Terror Twins were excited but this distraction allowed Black Lightning to shock them. Tuppence recovered and caught Nightwing off-guard, as he led the prisoners out. She then started to attack Tigress by shrugging off her arrows until the latter had the prisoners get out the building. Along with her brother, she prepared to corner the heroes but Geo-Force and Tara came to the heroes' aid by blocking the villains' path to prevent pursuit.
Super strength: This is one of the Terror Twins' main abilities. This allows them to easily pick up or carry heavy objects. The Terrors Twins were able to battle Superman and the other powerhouses of the Justice League.
Super leap: Their strength also allows them to jump over great distances and to great heights.
Invulnerability: Both Tuppence and Tommy have great durability and are able to take punches from Superman and Superboy with very little physical damage to their bodies.
Tommy and Tuppence Terror are named after the characters Tommy and Tuppence, a couple of married detectives created by Agatha Christie. The name is also a nod to Greg Weisman's friend Tuppence Macintyre, who had previously helped him research Scottish history for the television series Gargoyles. Greg had previously created another character based on Tuppence Macintyre while writing Captain Atom: Plastique's lawyer, Tuppence Macrae.
In Young Justice #0, Tuppence had short hair. In the comic, she was drawn by Mike Norton based on a rough design (concept art) by Phil Bourassa. For the show, director Jay Oliva wanted her to more resemble Gwen Stefani, partly to differentiate her from Shimmer, so she was redesigned by Phil Bourassa.