|Out of universe information|
- "Everytime we get involved with you, I feel like I'm walking around with a live grenade in my pocket, just waiting for it all to go wrong - for that one thing you forgot to mention [...] If I find out you're playing us, I'm not going to wait for authorization, there isn't going to be any paperwork, I'm just going to kill you."
- —John Sheppard to Todd.
"Todd" is a Wraith with whom the Atlantis Expedition has made contact several times, sometimes as a worthy ally, sometimes as a cunning adversary. He is distinguished by a starburst-shaped tattoo centered around his left eye, and his cynical, biting sense of humor. He formally introduces himself as "Todd", recognizing John Sheppard's naming him as such, although his true name is unknown. A skilled negotiator and tactician, Todd commanded one of the larger Wraith factions in his race's civil war, but its status is indeterminable after his betrayal at the hands of a subordinate and its attack on Earth.
Before his capture, Todd was a Wraith of some political standing; after being freed he is in loose command of about a dozen Hive Ships (out of at least 60 in the galaxy), and these had remained loyal to him during his imprisonment, implying that he used to command even more, most probably because he is over 10,000 years old. . He notes that his time spent in Commander Kolya's prison diminished his standing among the Wraith, further supporting the notion that he held a great deal of influence beforehand. He's also an adept scientist, having a significant understanding of nanite coding and Wraith technology in general.
When first introduced, "Todd" (then unnamed) first appeared as a prisoner of the Genii forces loyal to Commander Acastus Kolya. As part of their plan to get the Atlantis Expedition to turn over Ladon Radim, the current leader of the Genii, Kolya threatens to have Todd to periodically feed on, but not completely drain, Colonel John Sheppard. He was allowed to feed on Sheppard three times only for several seconds to force Elizabeth Weir to give him Ladon Radim, before they finally conspired together to escape the Genii prison; Sheppard having given Todd a new sense of hope. Working together, the two overpower Kolya's guards and escape, only to be cornered as they approach the Stargate. In order to gain the strength to fight them off, Todd almost completely drains Sheppard, leaving him barely alive but allowing Todd to easily kill the Genii soldiers approaching them. To repay Sheppard for freeing him, he drains the Genii soldiers he overpowered and uses their life-force to regenerate Sheppard which he referred to as the Gift of Life; Doctor Rodney McKay even claims that Sheppard looks younger than he did before. Sheppard, in turn, leaves Todd on another planet to link up with his hive. Both he and Sheppard agreed to honor their deal of letting the other go with Sheppard warning Todd again that should they meet again, they would be enemies. Todd suggested that it would be good, for both their sakes, that they never meet again. 
Todd returned a year later to forge an alliance with Atlantis Expedition against the Asurans, with whom the Wraith were now at war, while also informing Atlantis of the Asurans new strategy of wiping out every human in the galaxy to deprive the Wraith of a food supply. Since the efforts of the Atlantis personnel have rendered the Wraith's previous virus ineffective in shutting off the Asuran Wraith-attack command, he needs their help to adjust it, jokingly offering to secure their truce with a handshake. He is stranded on Atlantis after the Hive Ship which brought him is destroyed by another suspicious Hive.
He remained in Atlantis custody for weeks, working with McKay on the nanite coding. He also agreed to help McKay in shutting down the nanites in Jeannie Miller's body, but only after he was allowed to feed on the man who had infected Jeannie. During this time on Atlantis, he hacked McKay's computer and took the macro for the Carter-McKay Inter Galactic Gatebridge (which was later stolen from him), allowing the Wraith to attack Midway Station and Stargate Command. 
Todd eventually secures his freedom when he convinces seven Wraith Hive Ships to join with Atlantis' two Daedalus-class battlecruisers and the Travelers on an assault of the Asuran homeworld. Todd uses the battle as a distraction to covertly steal several ZPMs from the Asuran homeworld the planet before it was destroyed, in order to power a massive Wraith cloning facility, which he wanted to use to create his own Wraith army able to wipe out his rival Wraith factions. He is, however, betrayed and imprisoned by a rival hive, set to be fed upon by a Wraith Queen once he outlives his usefulness. Sheppard's team locates his damaged ship and frees Todd, and together they destroy the facility by ramming it with the damaged Hive-Ship. He escaped this hive ship on a dart separately from Sheppard's team. Later, it is revealed that Todd provided information to a Wraith faction allowing them to attack the Midway station and Stargate Command, implying that he conducted espionage on the expedition during his stay in Atlantis, and that he is still alive. This is later confirmed when random outbreaks of a modified version of the Wraith-poisoning inoculation prompt Todd to arrange another collaboration in order to stop the threat to both races. When confronted with his apparent involvementin the Midway incident Todd admits to stealing information from McKay's laptop, but insists that the Wraith who planned the Midway occupation stole the information from him in turn. Given his shock over their accusation that he had something to do with this, he was likely telling the truth.  Later on, Todd has invited Colonel Sheppard's team to his hive ship to discuss a possible "cure" for feeding. He agrees to this, but insists that they need the support of the Primary, the lead Wraith in his alliance. He reveals that there is a slight problem to his plan--the Primary will only meet with the queen, who was killed a year ago when his Hive Ship was destroyed. He reveals that they, however, do not know this; he essentially bluffed his way into the alliance. There is only one person who can do this; Teyla, having Wraith DNA, is the only person who can pose as a queen without instantly being detected. She agrees and the two set off. Todd tells Teyla of how there are great differences between her people and the Wraith. They meet with the other hive ship and the queen--it is then that Todd kills the primary queen and explains to Teyla about how the queen would not have accepted their proposal. Teyla later engages another Hive Ship in combat, at which Todd remarks how she is doing this intentionally--to kill Wraith. Things get complicated when the commander of the Hive Ship learns that Teyla is not who she appears to be. Todd saves her, but they have an argument later about it. He is left in command of the ship, and, with Teyla giving him full authority, effectively leads the Wraith alliance. The team later comments on how it could have been his intention all along. 
Later, Jennifer Keller founds a gene therapy within Michael's database that should eliminate the Wraith's need to feed on Humans again. The Expedition invited Todd's Wraith faction to discuss this major discovery.
Meanwhile the Atlantis Expedition discovers the Lantean, Janus', secret lab in Atlantis. The Drs. Rodney McKay and Daniel Jackson unknowingly activated a signal alerting the rogue Asgard-faction, the Vanir, of their location. The members of the Vanir forced Daniel Jackson and Rodney McKay to activate the "Attero Device", which destroys any Wraith ship going into hyperspace.
This caused a duo of Wraith cruisers to be destroyed and Todd to believe that the Atlantis Expedition had located and deliberately activated the device. Believing he was betrayed, Todd hijacked the Daedalus.
Three Vanir starships, the hijacked Daedalus and one Traveler ship would confront each other around the planet M6H-987, where the device was. The Lost Tribe lost two starships in the battle, the Tau'ri re-took the Daedalus and the Attero Device was destroyed. Todd and his Wraith escaped the Daedalus on a Wraith Scout Ship before the battle started. 
He was forced to work with the Expedition once again when his Hive appeared in orbit over the planet where Atlantis is. Turns out that he had stolen and injected himself and his crew with the experimental drug created by Jennifer Keller. It took away his ability to feed but also gave him a disease, like cancer. The disease spread to his Hive Ship when in symbiosis with the crew during stasis. His Wraith Soldiers turned feral and tried to eat several humans, they were all killed by the humans. He managed to succesfully land the hive in the water. John Sheppard told Richard Woolsey to let him go find his cure, to have an Iratus Bug Queen suck his blood. He was released and left Atlantis on good terms. 
Later he contacted Atlantis revealing that, though the process was extremely painful, the Iratus bug had completely cured him of the horrid disease, also reversing the gene therapy causing him to turn back into a normal Wraith. He also revealed that he had been shot down by one of his crew, who had gotten his hands on several Zero Point Modules, a vast power source that can strenghten a Hive greatly. He was allowed back to Atlantis, but was held in a cell for interrogation pending a decision about his fate. The Wraith that betrayed him was on his way to Earth, having received the coordinates from a subspace transmission from an alternate reality. With some inside knowledge from their on-again, off-again ally, the Expedition was thankfully able to destroy the superhive before it could attack the planet directly, though the victory came at great cost to the fleets of both the Travelers and humanity.
Todd's personality is unusual for a natural pure-blooded Wraith. He is reasonable, surprisingly loyal, and to a degree quite honorable, keeping his bargains rather than manipulating them. He is far more willing to make compromises and deals with humans and acts far less arrogantly in their presence, serving in many ways as the Wraith version of the Goa'uld System Lord Yu, as both were willing to work with Earth's forces to achieve mutual goals. During his imprisonment with Sheppard, he commented that it would be worth escaping just to see the stars again, implying that he has a sense of beauty and appreciation of freedom. He also seems to regard the act of feeding as more of a necessity than an act of sadistic pleasure. He also attempts to justify the Wraith's actions when it comes to feeding by describing the hunger a Wraith feels has the equivelent to being on fire and asks Shepered "Tell me, Sheppard, if you found yourself burning alive, would you settle for just one drop of water ...or would you take more". More recently, due to his continued presence among the Atlantis teams, he seems to have developed a grudging respect for the teams' various abilities. During Teyla's telepathic struggle with a Queen, he is seen looking on with a degree of surprised admiration. It is unknown how much of his personality is due to his long imprisonment and contact with humans. He still retains considerable standing among the Wraith, although it has significantly waned.
- "Wraith are never ending!"
- —Todd to John Sheppard
- In the alternate future Sheppard learned about Todd's final fate when he accidentally traveled 48,000 years into the future. It is revealed that Todd died fighting alongside Ronon Dex in an attempt to destroy one of Michael's research facilities. This is ironic in a poignant point of view, as Ronon had always held a begrudging resentment towards Todd since they first met. It is possible the two may have come to terms with one another, seeing as they had a common enemy to deal with at the time. 
- In another alternate reality Todd is seen in the captivity of the Tau'ri. He had been captured when his hive that had attacked Earth was destroyed and his dart had crashed. The Tau'ri kept him in a cell but hadn't fed him, which had made him delusional from starvation. This version of Todd seemed to be quite poetic.