Dr. Z (Dr. ソーノイダ Dr. Sonoida) is the main antagonist in the first series of Dinosaur King, as the leader of the notorious Alpha Gang. However, after being betrayed by his long-time comrade, Seth, Dr. Z changes his ways and joins the D-Team's cause.
Dr. Z is zany, egotistic, and evil leader of the Alpha Gang. He plans to use the dinosaur cards in his plans to be the dinosaur king. Dr. Z is also very short tempered and very little at listening to what should be done if its beyond Alpha Gang themselves keying in his stubborness, this can be shown in the series where Dr. Z refuses to apologize for what he did to Rex and his parents. It can pointed out in some cases that Dr. Z can quite stingy claiming everything to his (this includes Rex's dinosaur tooth necklace). But before his antagonistic persona; In his youthful years he was a kind, but generous man as he had adopted the Alpha Trio and Rod and Laura's father from an orphange raising them as his kids.
Dr. Z often sends the Alpha Gang to obtain dinosaur cards (which were scattered when his time machine exploded) for him. He stays in his lab on Zeta Point, researching and experimenting with the dinosaur cards that he already has, unless it's a special occasion, most notably the activation of a Secret dinosaur. He created the Secret dinosaurs, as well as the Alpha Gang and D-Team's Element Boosters. He creates many machines and devices for Ursula, Zander and Ed, but the often break apart or otherwise fail. It is shown that he cares dearly for his grandchildren, as shown when they are captured by plants and he screams "Help is on the way!"
Dr. Ancient hired Dr. Z (along with Ursula, Zander, and Ed) to help him turn dinosaurs into cards to save them from a terrible disaster. They got along great at first until Dr. Z started making the dinosaurs fight each other for his own amusement. Later, Dr. Z teamed up with Seth, who was an assistant for Rex's parents, to get rid of them so they could use the cards any way they wanted. During all the commotion, baby Rex was sent flying out of the time machine (Zeta Point) along with his parents, only Rex went to the past while his parents were sent flying back to the future. Almost immediately after this someone broke the time machine sending the Alpha Gang a few years later in the past where Rex is now a 12 year old boy. It is also revealed that Dr. Z saved Rex's parents feeling bad for them, but kept it hidden from everyone else. During his younger days, Dr.Z adopted Ursula, Zander, and Ed, as well as Rod and Laura's father when they were young. He made a great foster father as he treated them in a pure-hearted way. He cares for mostly Rod and Laura, his grandchildren. He created 4 Secret Dinosaurs (6 if you count Dano and Sue), although all of them rebel later on.
In episode 46, Seth betrayed Dr. Z by threatening him with his Saurophaganax and his Fire Scorcher move card, defeating both Spiny and Tank easily. He joined the D-Team's cause and he helped defeat the Black Tyrannosaurus by using Terry, Saurophaganax and Daspletosaurus against it. In Mesozoic Meltdown/Pterosaur Legends, he randomly comes down from the Backlander to help, other times he stays in the ship, working on projects or taking naps in his bed. After Mesozoic Meltdown episode 21, he gains the obsession to get all the Cosmos Stones and harness their power and use it to become Dinosaur King. In the finale, Dr. Z finally manages to create a Dinosaur Kingdom and become Dinosaur King by rescuing Dinosaurs from Spectre's ship.
Dr. Z is the final boss in the DS Game. He uses Fire Dinosaurs like Tyrannosaurus, Mapusaurus and Saurophaganax (2). In the finale Arctic game if you favor a rematch, he uses two Saurophaganax and an Eoraptor.
- (DKSS/DKCG) Choose a Dinosaur in your discard pile and Dino Slash it. Then, search your deck for a Move or a "Terry" and put it into your hand. (Shuffle your deck after you search it.) You can include "Terry" in your deck only if you are using this Character.
- (DKAA) Choose 1 of your Alpha Dinosaurs. It gains +500 Power the next time it battles this turn. Then, search your deck for an Alpha Dinosaur or a Move and put it into your hand. (Shuffle your deck after you search it.)
- (DKBD) Choose 1 of your Alpha Dinosaurs. The next time it battles this turn, it gains +400 Power and gains [Bite] if it does not already have [Bite]. (If it wins the battle, your opponent loses 1 extra Life Point.) Search your deck for a regular Move card and put it into your hand. (Shuffle your deck after you search it.) You can include "Terry" in your deck only if you are using this Character.
- Dr. Z owns underwear with a picture of Helga's face on it. Helga has shown her disapproval of the placement.
- He once had a turtle named Sue. This led him to eventually name one of his Deinonychus after the name.
|D-Team:||Max Taylor · Rex Owen · Zoe Drake · Spike Taylor · Reese Drake|
|Alpha Gang:||Dr. Z · Ursula · Zander · Ed · Rod · Laura · Helga|
|Spectral Space Pirates:||Spectre · Gavro · Foolscap · Sheer · Goma|
|Others:||Seth (left Alpha Gang and Spectral Space Pirates)|