|“|| That's some serious danger you're facing. It sounds like at least two of the five are going to die.
–Connor, in The Titan's Curse
Connor was born the second child of Hermes and an unnamed mortal woman after his brother Travis, making them one of the rare non-twin full-blooded demig siblings.
At an unknown point they were brought to Camp Half-Blood for training.
Because Luke Castellan betrayed the camp, Connor and Travis Stoll became the leaders of the Hermes' Cabin. Percy says he can never remember who is older, although later in the series it was revealed that Travis is the older sibling. Percy said that he always thought it funny that Hermes would have children with the last name "Stoll", but when he mentioned it to Connor and Travis, they both stared at him blankly as if they did not get the joke.
In the Chariot races, Travis and Connor man the Hermes chariot. Percy states that he shudders to think what schemes they have cooked up. Unfortunately for them, right after the race begins, they ram into the Apollo chariot and both chariots flip over.
In the next race, the Stoll brothers attack Clarisse La Rue in the Ares Chariot with javelins. They fall behind as Connor has a fierce fight with Clarisse as Travis drives. They end up coming in third, behind Percy's chariot and the Ares chariot.
When Percy first arrives at camp, he sees Travis and Connor trying to pick-lock into the camp store. In the game of Capture the Flag against the Hunters, they are both on defense with Percy and a few others. Unfortunately, they both get wounded by the hunter Phoebe and Connor ends up with two arrows in his helmet "like antennae."
Later, when Chiron calls a meeting, Travis and Connor go to represent the Hermes cabin. Connor remarks that they are facing a lot of danger and he and Travis give Zoë Nightshade a collector's T-shirt to give to Phoebe. It is later revealed that the T-shirt was sprayed with poisonous centaur blood that Aphrodite gave to them so that Percy could go on the quest.
When Percy arrives at camp, he sees Connor and Travis in the driveway of the Big House, trying to hot-wire the camp's SUV. In the scorpion war game, they are paired together, which is no surprise, because they do everything together.
They both attend the war council with the other head counselors of the other cabins. They both fight bravely in the Battle of the Labyrinth and both survived.
Connor and Travis are both interviewed by Rick Riordan, they tell him about the Golden Mango prank they pulled on the Aphrodite Cabin. They tossed a mango painted gold into the cabin with the words for the hottest on it so they would fight each other for it. they did and apparently "Gucci shoes were flying out of Windows and it was a full on fight". They ended up getting busted, however, and the Aphrodite campers had a curse put on Connor that made all his clothes two sizes too small for him. He says he felt like a geek.Travis mentions that he is a geek.Travis was hit with Permanent Makeup.
This prank mirrors the Eris' prank that was pulled on Athena, Hera, and Aphrodite by tossing a golden apple between them and the three fought over it, eventually leading to the Judgement of Paris and the Trojan War.
When Percy returns to camp from his mission with Beckendorf, Connor is on lookout duty. He is the first person to see him, and when he does he gets so excited he falls out of his tree and runs to greet him. Although he is happy Percy is alive, his smile fades when he learns of Beckendorf's death. Together they climb the sand dunes to tell the rest of the camp the news.
He and his brother attend the war council that Chiron calls. Neither of them seem to be bothered by the fact that Clarisse is not speaking to any of them. When Percy mentions that there is a spy, Connor says that they have suspected a spy for years and that it is probably someone who knew Luke well. He glances at Annabeth Chase, but then quickly looks away, stating "It could be anybody."
It is revealed that the Stoll brothers have somewhat of a rivalry with Katie Gardner, the head counselor of the Demeter cabin, ever since they decorated the roof of her cabin with chocolate Easter bunnies. Travis and Connor both get very angry when she suggests that the spy is one of Luke's siblings. Percy suggests that more gods should protect Olympus, but Connor tells Percy that if Typhon reaches Olympus, it will not matter who is guarding it. He later attends Beckendorf's funeral.
He comes along with most of the camp when Percy calls them into the city and they go up to Olympus. Their father, Hermes arrives and is not happy. It is unknown if this was the first time he and Travis met him, but they did not speak to him, and are happy when Annabeth tells them to lead the group into the city, giving them an important job right in front of their dad.
After a while they run back in and show Percy and Annabeth that Morpheus put the entire island of Manhattan to sleep. Both brothers are interested in taking advantage of the sleeping city and raid a candy store, which Katie Gardner scolds them for. Connor takes half of the Hermes cabin and defends the Manhattan Bridge. Most of them survive.
It is Connor who gives Percy the message that Grover Underwood has been found. He stays in fairly good shape throughout the battle, not being seriously wounded and continuing to fight throughout the battle, implying he is a decent fighter. After Silena Beauregard's death, he and Travis ask Percy about her death. Percy refuses to let her be known as a spy, although they had already heard it. They discuss the advantages of the elevator and tell him they already tried to disable it, but were unable to do it. Connor complains that there are no more reinforcements, giving Percy the idea to send a message to Nico.
After the battle, Travis and his brother come to Olympus and report to Percy that his parents and Chiron are alive. Connor ultimately survives and Travis does as well, with only minor injuries and they head back to camp to share the duty as the counselors of the much-less-crowded Hermes Cabin. Both brothers were involved on the eavesdropping of Percy and Annabeth and it was Connor who has the idea of throwing them in the lake.
Connor, for some unknown reason, was not seen in the final chapter when the council was summoned. His brother, Travis, was seen alone trying to light a ping-pong ball on fire.
Annabeth mentions Connor when thinking back on all the times spiders had scared her. She remembers the time she almost killed Connor for putting a tarantula in her bunk.
Nico briefly sees Connor in a dream where he was gathered in the game room with all of the other camp counselors discussing whether or not to fight the Romans. When Clarisse suggested they go out and attack, Connor vetoes her idea, saying they should do as Annabeth told them and says that since she sent them a note from "fricking Tartarus", he told Clarisse he would listen to Annabeth, holding great respect for her. He was later shown surrounding Jason for no apparent reason, fighting monsters alongside with him.
In The Hidden Oracle, it was stated that Travis has left the camp, and gone to college. His brother Connor is now the only head counselor of the Hermes cabin. According to Chiron, Connor has mellowed a bit, now that his brother is gone. And he is not so fanatic anymore, when it comes to pranking. However, that was no problem, because his siblings were more than happy to take over the pranking duties.
Later, Meg McCaffrey poked Connor in the eye, though it was unknown why she did so. As a revenge, Connor and Sherman Yang, who also was humiliated by Meg, tried to throw her into the lake. This failed, because Meg got defended by her Karpoi, Peaches.
|“||They are both so unlike my old enemy, Luke that it's hard to believe they're all sons of Hermes.||”|
Connor is tall and skinny with a mop of curly brown hair that hangs in his blue eyes. Like Travis, he wears an orange camp T-shirt untucked over baggy shorts. Like most of the other children of Hermes, he has elfish features, upturned eyebrows, a sarcastic smile and a gleam in his eyes, like he was ready to "drop a firecracker down your shirt". He has a crooked smile to match his personality and crooked sense of humor. He is also a little bit shorter than his brother, Travis, which is the only way people can tell them apart. In The Hidden Oracle, Peaches rips out most of Connor's hair.
Connor is a reasonably powerful demigod, though not as powerful as his half-brother Luke.
- Fighting Skills: Connor is implied to have good fighting skills during The Last Olympian, since he stays in good shape throughout the entire Battle of Manhattan.
- Cunning: Connor is uncommonly cunning, and, together with his brother, is usually able to get away with their outrageous and mischievous pranks. Also, Connor appears to be smarter than Travis, while the latter is the more mischievous of the two.
- Enhanced Theft Abilities: Connor is able to supernaturally steal things without people noticing, even other demigods.
- Clauditiskinesis: Connor can magically sense the internal structure and mechanisms of any lock he touches, and is able to make it unlock, even telekinetically. Hence, Connor and Travis have no problems with high-jacking the camp's SUV in The Battle of the Labyrinth. This does not work on cursed locks, though.
- Lock Intuition: Connor can also identify curses and traps placed on locks. If he concentrates hard enough, he can deactivate them.
- Money manipulation: Since Hermes is the god of merchants, Connor is quite good with money, and is really fond of playing poker as a result. He even tries to convince Nico di Angelo that poker is a much better game than Mythomagic in The Titan's Curse.
Percy commented on the irony of his last name being Stoll, as in stole, even though he and his brother did not get the joke. In Dutch versions the last name of the Stolls is Stall; you can derive this from the past tense of "stelen": the Dutch verb of to steal, or from stall: stable, since Hermes is also the god of animals. This last one is also the irony Percy commented on in the Dutch versions. In the Hebrew version of the book, his last name is שוד (Shod), which is the Hebrew word for robbery. In the Polish version of the book, Connor's surname is Hood, a reference to The Prince of Thieves, Robin Hood. However, on Riordan's website, he mentions that Connor (as well as Nico, Miranda, and Travis) was a former student of his.
His name is also a play on 'Con' and Hermes is the God of Thieves.
- It is said by Percy in The Sea of Monsters that the Stoll brothers are not twins, with Travis being the older sibling. However, the two look almost identical, only being differentiated by their height.
- Travis, along with his brother, were the only known named children of Hermes who were not ever on Kronos' side (whether or not Cecil has been on Kronos' side is unknown, and Alice Miyazawa and Julia Feingold joined camp after the war).
- Connor and Travis are somewhat similar to Fred and George Weasley from the Harry Potter series, in that both sets of brothers are good friends with the protagonist of their series (Percy Jackson and Harry Potter respectively) and have a penchant for outrageous and mischievous pranks.