Siobhan McDougal was the first-born child of Garrett McDougal, the patriarch of an old Gaelic clan that has occupied an island midway between Scotland and Ireland for a thousand generations. On that island is Castle Broen, where first-born McDougals undergo a ritual to prove themselves worthy to lead the clan. When Siobhan was young, she traveled the world, only returning to Castle Broen when she heard of her father's death.
Her uncle Seamus determined that no woman would lead the clan and intended her brother Bevan to become the new patriarch. She went ahead with the family ritual by herself, which involved calling on supernatural forces for power. She was interrupted by Bevan, and the distraction proved disastrous as she was dragged away into an infernal netherworld. An entity called "the Crone" granted her powers and the ability to return to Earth as the Silver Banshee, but demanded payment in the form of an occult book that belonged to her father. She found that her father's book collection had been shipped off for sale in the United States.
Her quest brought her to Metropolis. Killing anyone that stood in the way of her search attracted the attention of Superman, who was able to defeat her when he realized that she could only kill a person once as she turned away from someone who resembled a previous victim; by faking his death, Superman was able to enlist the Martian Manhunter to attack Banshee by posing as Superman's ghost. Unable to defeat Superman, she chose to retreat and continue her mission at a later date.
Silver Banshee returned to Metropolis twice more, but was halted both times by Superman. It was Batman who finally found the book among some stolen goods in Gotham City. Superman brought the book to Castle Broen where he was confronted by Silver Banshee. The Crone appeared at the castle, and after an enigmatic warning to Superman, she dragged the Banshee, Bevan, and Seamus off to her Netherworld.
In Leesburg, Supergirl rescued Silver Banshee from Satanus' Netherworld when the chaos flow brought the river Styx to the town. Silver Banshee was left in a confused state, eventually going back to her psychotic persona and using Supergirl's friend Mattie as a host while rampaging on the streets. Mattie and Silver Banshee thus proceeded to nearby Schnaffenburg where Mattie tried to get revenge on Gerald McFee, who killed her brother during Final Night while in thrall to Gorilla Grodd. Supergirl calmed Silver Banshee, separating Mattie from her, which led to Silver Banshee temporarily vanishing.
Silver Banshee was one of the final four villains- along with Bizarro, Mongul, and the Master Jailer- sent against Superman by Manchester Black, Black using his powers to make Banshee and Bizarro sane enough to tactically out think Superman, also granting Banshee awareness of his Kryptonian name so that she could use her magic against him more effectively. Despite this, Superman was able to defeat the four, forcing Mongul to expend his energy before dropping a nuclear-powered superhuman onto the deserted island that they were currently inhabiting.
Silver Banshee attempted to collect the billion dollar bounty President Luthor placed on Superman’s head in Superman/Batman #3, but failed, with Batman using an ultrasonic generator to keep her nullified.
Silver Banshee later joined the Secret Society headed by Alexander Luthor. She was one of the members who turned on Black Adam when Luthor needed him for his machine. She also took part in the Battle of Metropolis.
Silver Banshee battles Supergirl in Supergirl #34, and is expected to be a recurring nemesis for Supergirl, as well as Superman, as part of an attempt to tie Supergirl's book in with Superman's titles.
In Superman #682, Supergirl was used as a diversion as some members of Kandor captured Silver Banshee, placing her in the Phantom Zone. Later, Superman freed Silver Banshee to be taken to Belle Reve.
Inspector Henderson with other police officers break into an apartment, but it explodes and then they find a corpse covered in runes. Kara meets with Inspector Henderson, who's following a case his old mentor was never able to close, and thinks it has to do with items Silver Banshee needs to lift her curse. Inspector Henderson finds his mentor had the item, but it embeds itself in Inspector Henderson's hand, allowing Silver Banshee to track him. Silver Banshee shows up and fights Supergirl, but Supergirl opens a package from Henderson and becomes possessed by a Banshee hybrid.
Banshee-Supergirl and the Silver Banshee battle each other as events are recapped. Supergirl tells Silver Banshee they hid the artifacts in people, in order to keep them hidden from her. Apparently all the items were hidden not as a curse, but as a test for prospective clan leaders. Henderson punches Banshee-Supergirl, which is effective because of the artifact in his hand.
Supergirl tries to exorcise the spirits possessing her but fails. Henderson realizes the spirits are tied to the artifacts and can be used against them. He then stabs his hand and breaking Supergirl free from her spirits. Silver Banshee then uses her wails to disperse the spirits. She finally uses magic to remove the artifacts from Henderson's hand and lets him know she is indebted to him.
The New 52
In The New 52 (a reboot of the DC Comics universe), Siobhan Smythe first appears in Supergirl vol. 6 #7 as a girl from Dublin who had immigrated to the United States to start a new life after her mother died, and to escape her father (the also dead Black Banshee). She befriends Supergirl, and stood up to the National Guard who tried to gun Supergirl down, as she could clearly see that Supergirl had saved the city from Kryptonian Worldkillers, but is the only one who can speak her language. She invites Kara to live with her, and brings her along to a cafe where she will perform music, when her dead father, the Black Banshee, attacks, prompting her to transform into the Silver Banshee. It is unclear at this time whether her alignment will remain good.
Powers and Abilities
Silver Banshee has superhuman strength, agility, speed, endurance,flight (through sonic waves) and a high degree of resistance to physical and energy-based attacks. Her incredibly strong and destructive hyper-sonic wails, sonic screams, and sonic yells can kill anyone within a certain range as long as she can see her victim and knows their secret true name. Victims are usually reduced to desiccated husks. Silver Banshee is able to use her sound/sonic-based abilities to teleport via sound waves.
As Siobhan Smythe in The New 52 continuity, she has also exhibited a gift for language, becoming fluent after hearing merely a few words in not just humanoid languages, but also animal languages (she shows off to Supergirl by talking to doves), though she tends to speak every language with a strong Irish accent.
In the limited series JLA/Avengers, Silver Banshee appears as a villain in Metropolis under Krona's control. She helps take down the Vision and Aquaman but is ultimately defeated by Wonder Woman.
JLA: The Nail
In the Elseworlds story JLA: The Nail, the Silver Banshee makes an appearance in Professor Hamilton's Cadmus Labs.
In other media
Justice League Unlimited
Silver Banshee appears in the Justice League Unlimited. This version can fly and can drain her opponents of their life energy at will which will age them in seconds. She is seen as a member of Gorilla Grodd's Secret Society as seen in "I Am Legion." In "Chaos at the Earth's Core," Silver Banshee accompanied Metallo to Skartaris to retrieve a large chunk of Kryptonite that is in the custody of Warlord and his allies. She is captured by Green Lantern after he uses his power ring to gag her. She escaped soon after being captured. Kim Mai Guest is credited for voicing Silver Banshee even though she has no identifiable dialogue. Silver Banshee is shown with the Secret Society shown on "Alive". As she is seen fighting on Grodd's side during his mutiny against Lex Luthor, but is not shown among those frozen by Killer Frost or the Darkseid's explosion survivors, it is likely she was killed by Star Sapphire during the mutiny, as she was seen hitting Silver Banshee with her laser and later firing numerous lasers in her direction.
Silver Banshee appeared in the Smallville episode "Escape" played by Odessa Rae. This version is a deceased Gaelic heroine who was cursed and placed in the underworld. Siobhan managed to escape from the Underworld, possessing great powers. Just like her recent appearances in the comics, this version needs to possess a host. She was released when Lois Lane accidentally ripped a portrait of Bevan (which had been painted over a portrait of Siobhan) at the McDougal Inn. Her abilities are sonic scream, superhuman strength, stamina and durability. When she utilizes her powers, her irises glow white.
She took over the body of a female guest and killed the woman's boyfriend. Afterwards, Siobhan possessed Chloe Sullivan, but was foiled to seduce Clark Kent.
Batman: The Brave and the Bold
A character named "Scream Queen" appears in the Batman: The Brave and the Bold television series. She is based on Silver Banshee, and her outward hooded appearance is similar to Raven.
Italia Ricci appears as Siobhan Smythe in Supergirl starting in episode 14. The character eventually becomes Silver Banshee and forms a team up with Livewire. Despite being the Smythe version, she is based on the McDougal version of the character, having long hair and acting as a villain/enemy to Supergirl.
Superman/Batman: Public Enemies
Silver Banshee appears in the animated movie Superman/Batman: Public Enemies. This version can also fly. She is one of the many supervillains that want to collect the $1 billion bounty that President Lex Luthor placed on Superman. She is defeated when Superman takes her to the upper limits of the atmosphere where she cannot breathe, and while she is unconscious, Batman puts a device on her that would nullify her power by turning it against her will.
Silver Banshee, along with Parasite, Brainiac, and Doomsday, were considered as the main villains in Superman Reborn, but the film was cancelled before it began production.
Batman Unlimited: Monster Mayhem
The Siobhan McDougal version of Silver Banshee appears in Batman Unlimited: Monster Mayhem, voiced by Kari Wuhrer. She (along with Scarecrow, Solomon Grundy and Clayface) joined the Joker's gang of monsters to wreak mayhem on Gotham City.
Suicide Squad: Hell to Pay
Silver Banshee appeared in Suicide Squad: Hell to Pay, where she served as one of Professor Zoom's minions.
Silver Banshee from Batman Unlimited: Monster Mayhem.
Silver Banshee in Superman/Batman: Public Enemies.