Leo Francis Dooley is the 15-year-old teen without any bionic abilities. He is considered a social outcast due to most circumstances considering his small amount of friends. Donald had a lack of trust for Leo due to accidental destruction caused by him, but has started to change his opinion. He is Tasha Davenport's son, Donald Davenport's step son and Douglas Davenport's step-nephew.
Leo is Mr. Davenport's stepson who knows about Adam, Mia, and Chase's bionics. His mother, Tasha, knows this as well.
He is portrayed by Tyrel Jackson Williams.
Leo is loyal, caring, and intelligent. He has demonstrated these qualities in various situations, especially when his family is involved. He showed his loyalty to his siblings by staying on their side despite the possibility of him getting hurt; by sacrificing his date with Janelle--and ultimately, his safety--when the possibility of them dying became imminent; and by keeping their secret of using their bionics at school despite its end result of him not being able to go to an event he's been looking forward to going to. He shows that he cares for them and about how they feel in isolated events, like when he allowed Chase to redeem himself by letting him use his idea to defeat the exoskeleton. when he apologized to Adam and Chase for showing them up at the dance. and whenever he bonds with Donald. Upon Donald's request, he kept watch over his siblings, especially when they were around Marcus. After finding out the truth about him, he became more alert for them, even risking himself once again to prove to his family the danger that Marcus presents.
His intelligence and problem-solving skills have come to play in several instances. Using his knowledge of science and street smarts to stop a high-speed train and applying the simple things he observes to drain out a toxic gas during a mission are two instances. Despite this, on several occasions he fails to take account of the potential consequences of his actions.
However, Leo can be manipulative and self-centered at times, which often stems from his unpopularity. He has taken advantage of his siblings' bionics multiple times. He has used Mia's view of him as her little brother to catch a ride to his classes and get his 'forgotten' homework; Adam's super strength to win the school fitness challenge; and the father-son relationship he's formed with Donald to be able to see a movie his mother forbade him to see. Leo also quickly turns arrogant if things start to go his way, and acts stuck up, normally leading to him falling back to the ground painfully. He also often blows his achievements or duties out of proportion, making himself out as far more important, popular and successful than he really is.
Leo also has a habit of creating his own problems; for example, he got trapped in Principal Perry's private elevator, which he was using despite students being forbidden or him convincing Mia to misuse her bionic vocal manipulation leading to both of them being discovered, or disabling Chase's bionics and inadvertently amplifying his bionic aggression. He also often lies, and uses lying to try and solve his problems, normally unnecessarily; however, this backfires on him as it has left others distrusting of, meaning he sometimes has trouble convincing them even when telling the truth, as demonstrated with his efforts to tell them Marcus is evil.
Leo has a crush on Janelle. In a possible future seven years from the present, Leo and Janelle are a couple. One time, he had a crush on Danielle, but he chose not to pursue that (in order not to hurt his brothers' feelings).
Adam is Leo's step-cousin/adoptive step-brother. They have a close brotherly relationship and are always there for each other. They do argue and insult each other sometimes, but in the end, they'll be there for each other, no matter what. Adam discovers his hidden ability when Marcus was about to kill Leo. These two care deeply about each other and will always help each other out, in any way they can.
Mia is Leo's older adoptive step-sister. Mia puts herself in a position as Leo's older sister, and makes him pay the consequences to his mistakes. She claims that she wants him to follow his responsibilies as she does with herself. They're always there for each other and care deeply about each other. Leo was worried about Mia when he said to Donald that if Mia doesn't make it, he'd be crushed.
Chase is Leo's step-cousin/step-brother by adoption. They have a close relationship and are always there for each other. They work together on some things, but can grow jealous/competitive with each other too. They insult each other a lot and bicker too. But when the time is right, they will help each other out in any way they can.
Donald Davenport is Leo's stepfather. Leo mainly calls him Big D because of his position as head of the Davenport Household. Mr. Davenport sometimes tries too hard to bond with Leo. Leo is Donald's lab assistant. He strategizes missions for the Lab Rats.
Leo's enemy was Marcus. (Marcus turned good.) Marcus antagonized Leo and threatened him since he considered him a hindrance to his plans due to his being aware of his hidden plans. Especially since Leo discovered their hidden lair, he showed more hostility towards him. Slowly but surely, Leo learned to trust Marcus after he saved Mia's life and helped kill Douglas.
Another enemy of Leo is Principal Perry. Both of them have seemed to unlike each other from the start. On one occasion, they momentarily stand each other. Leo would like to stay away from Principal Perry at all costs, as she likes to punish him.
Leo strongly hates Douglas because Douglas kidnapped Mia multiple times and wanted to make her into his perfect soldier.
Not much is said about Leo and Robert's relationship, but clearly it's known that they strongly hate each other.
Enhanced Reflexes: Although he has no bionic abilities, Leo has reflexes that are far superior than the average person, which allows him to easily dodge and/or deflect laser bolts (even from weapons geared to destroy superhumans and controlled by a supercomputer), and redirect those laser bolts to strike even small targets with pinpoint accuracy. He says that he developed those reflexes because of his life-long love of playing video games.
Intelligence: While not in the same class as Chase, Mia or Mr. Davenport, Leo is a very intelligent kid. With all of the advanced skills he's developing as a result of his new life, it's possible that Leo could become even more intelligent.
Tactical Thinking: Leo has a gift for sizing up a situation and coming up with solutions, even while under extreme pressure. Also, because of growing up less sheltered than the other kids or even Mr. Davenport, Leo's instincts about people are far sharper, allowing him to size up people very quickly. (Leo immediately recognized Marcus as a threat, and Marcus, in turn, considered him a serious enough threat that he tried to eliminate him and threatened him with exposing the entire family to the world when he couldn't eliminate him outright.)
Bravery: Despite his childish attitudes, Leo has a strong sense of courage. He didn't hesitate to push all three siblings to safety when they were nearly killed by falling debris (almost being killed himself), and one time. he went into a dangerous situation to help Mr. Davenport stop a toxic gas leak (while Adam, Mia and Chase were being kept in detention at Mission Creek High School by Principal Perry). Leo also stood up to Marcus, even after being threatened with Marcus' laser vision.
Computer Knowledge: In some instances, it is shown that that he seems to know how to hack into computers.
Electrical Generation (Parallel Universe): One time, Leo gains this in the world where he is bionic. He harnesses the static electricity from his surroundings and utilizes it to create lightning bolts, much like Mia's lightning power.
Super Speed (Parallel Universe): Leo uses this ability three times, all in an effort to either escape or to defend Mr. Davenport and himself.
Super Intelligence (Parallel Universe)
Super Strength (Parallel Universe): This ability manifested once: when Leo tosses the keys to Tasha and he ends up shooting them through the door, knocking off the neighbor's mailbox.
Geo-Leaping (Parallel Universe): Mr. Davenport reveals to Leo one of his newly uploaded abilities as they attempt to escape. Leo molecularly transports himself (and whoever he touches) from one place to another by thinking about his destination.
Martial Arts (Parallel Universe): It is shown that Leo can use martial arts like the Lab Rats but it seems he can only use martial arts when he was bionic.
Physical Inferiority: Because he is so small and tiny, Leo is virtually physically weaker than most people.
Normal human: As he is not bionic and lacks the durability and abilities that comes with being bionic, he is constantly at a disadvantage in many if not all situations.
Self-defense incapability: Unlike Adam, Mia, Marcus, and Chase, and Mr. Davenport, Leo is not taught in martial arts and does not know how to fight. He has to rely on technology or other things to defend himself. He is also considerably small, which is another problem.
Bully victim: Because of his size and how unpopular he is, he is a very easily-targeted bully victim.
Inexperience: Leo's inexperience on missions makes him very vulnerable to danger.
Arrogance: Leo can be quite arrogant at times, especially if things start to go his way; more often than not he will blow his good luck by being arrogant and pushing it too far.
Creating his own problems: Leo has a habit of creating his own problems, although this is normally accidental and usually stems from him not understanding or atticipating the implications of what he is doing.Clumsiness: Leo is always curious about something that can go wrong.