Rob is the secondary, later true main antagonist of The Amazing World Of Gumball, and Gumball's sworn enemy. He is formerly a tall blue cyclops,and is now a disfigured white cyclops. He is a minor character in season 1, a half antagonistic character in season 2, a minor antagonist in season 3 and the main antagonist of season 4 and the main villain onwards, taking Miss Simians role as the villain. Rob also became Elmore's newest threat, also becoming Gumball's archenemy as of the episode The Nemesis. He is the main antagonist of the episodes The Nobody, The Nemesis, The Bus, The Disaster, and The Rerun. Although, he hates both of the Watterson brothers and everybody in Elmore, Rob is shown to be more focused on killing Gumball and not Darwin as shown in The Bus.
Rob's most prominent feature is the large eye at the center of his head. In Seasons 1 and 2, Rob was blue with brown hair. He wears an orange-sleeved yellow shirt, and red shorts. He also wears a brown backpack. His hand are pink and he wears brown shoes with gold laces. From going through the void, he became a disfigured white cyclops. His skin tone had changed from blue to white. His left shoe and hand turned black. His right shoes is reduced to chartreuse wireframe. Parts of his face displays distorted static. His eye is pale-yellow and has two stuck pupils. His hair turned polygonal and turned solid brown. His shirt has turned sleeveless.
Rob is usually nice and social, but is extremely offended when people forget his name or walk away from him. In "The Nobody", he has no memory of his past life, and thus feels like a nobody. At the end of this episode, Rob remembers what happened in his past, and he swears vengeance on Gumball and Darwin for leaving him behind. Although he seems threatening when he claims revenge, he later proves to be very incompetent at defeating the main characters in "The Nemesis" where he was shown to have multiple failed attempts of harming Gumball and Darwin, and even needs help from them to make him a better villain (which even then doesn't help him much). Afterwards, Rob was more evil and is now focused on defeating Gumball more.
Rob first had a cameo in Rachel's party with other Elmore Junior High students. He is later one of the Elmore students to watch the fight between Gumball and Tina Rex. Rob later appeared trying to say hi to Gumball and Darwin, but they end up ignoring him and kicking him into a manhole. He also denies them the DVD they were after. Rob is later in a crowd of angry Elmore civilians trying to attack The Wattersons before reality is fixed. Rob then appears as one of Elmore's mistakes sent to the Void. Years later, in "The Nobody" a mysterious guest steals all The Watterson's possessions including: Nicole's money, Anais's Daisy the Donkey doll, and Richard's toothbrush and toothpaste. The three members of the family blame Gumball and Darwin for stealing those possessions and Nicole punishes them by making them stay in their room while they're away until they confess. The duo then try to find the mysterious house guest after he passes by them. This leads them to the basement, where they find all the stolen possessions that the mysterious stranger has stolen. They later chase him throughout Elmore, and prevent his escape by throwing condiments at a car, Tina, and a truck driver. This causes the stranger to surrender. Gumball and Darwin then ask the stranger about why was he in their house. He told them he has no place to live, and is nobody. He also tells them that he doesn't have a mom or any siblings. They try to say which the stranger can be, but to no avail. They then tell the stranger that he can be a bad guy and be their mortal enemy. They also tell him that he can be the worst mistake ever made. This triggers the stranger's memory and he is revealed to be Rob. Rob was trying to get Gumball and Darwin's attention, but they ignored him to find Molly. As the group left on Mr. Small's car Janice, Rob clung on to the back of the van as it drove back to Elmore. After the group drove off, Rob popped out and ended up disfigured in the process. He then vows revenge on Gumball and Darwin for leaving him, claiming that he will take away everything that they ever loved.
Rob's next appearance, in "The Nemesis" involves him failing to exact revenge on Gumball and Darwin. The duo decide to help him become a better nemesis by altering his voice, making him an outfit, and giving him a name change. Rob comes to call himself Dr. Wrecker and coins a new catchphrase: "You just got wrecked". Later in the episode, his plot to flood the town backfires when he is unable to escape via bus, so he consults Gumball and Darwin to help him. As all hope seems lost, they realize Elmore doesn't have a dam and Dr. Wrecker just destroyed part of a vending machine. In order to cheer him up, Gumball and Darwin walk into one of Rob's traps set up earlier. The cyclops then walks off in evil laughter as the two beg him to help.
Later on, Rob made 2 cameo episode appearances in The Uploads and The Love.
In "The Bus", involves he is revealed to be the one in charge of the adults plan to teach the kids to not skip school. His reason for doing this was not to teach the kids, but rather to get money and exact his revenge on the duo. Later in the episode, him and Gumball have a fight at an airport over two briefcases (which were also used as their weapons), one containing the money and the other holding a bomb. Rob is about to kill Gumball, but the police arrive, and scared, he blames Gumball saying that is the cause of everything. He runs off with the suitcase, only for that suitcase to be the bomb, which then explodes from the distance. This causes Rob to fly and fall onto a police car, where he is then arrested for his crimes.
Rob returned in The Disaster, presumably escaped from prison and found a remote that can control the universe. When the man from the Magic Van wanted the money he owed to Rob, he killed him by erasing him with the remote. While the Watterson family were finding a parking spot, Rob paused the scene and reminded Gumball that he will destroy everything he loved, and turned on all the car lights, crashing the family's car in a wreck. While at Elmore Mall, Rob made Gumball lose his brother, Darwin by subtitle insults, making Gumball cry and running to his family about what happened, Nicole calms him down. Then Rob made Richard and Nicole break up and went their separate ways, and he made Gumball break up with his girlfriend, Penny, and pushing her to her death, and Rob paused the scene. Gumball confronts Rob and wants his revenge on him for messing up Gumball's day. The two battled and fought. Rob explained that he wanted to be the sidekick of Gumball, not a villain. Rob hits the eject button opening a portal to the Void, nearly pushing Gumball in it. Rob tosses the remote in the Void, and Gumball had no other choice but to fall in the Void and get the remote. He succeededly hit the rewind button, sending Gumball right back to the beginning of the episode, and a "To be continued..." message appeared.
Rob appeared again in The Rerun, where Gumball must stop him from destroying his life. However, he fails this, as even he manages to save Darwin and Anais, he accidentally uses the remote and rewinds his parents to their baby form, causing Darwin and Anais to get erased from existence, Gumball attacks Rob and then throws him into the void. Realizing he is the villain now, Gumball jumps in the void as well to save Rob. However, he does not let this and only tries to kill Gumball again. At the end, however, Rob realizes that he can't kill him because Gumball just wanted to help him. He rewinds and pauses at the time before they fell in the void and makes ammends with him. However, Rob then states that he will rewind back to when he got the remote and destroy it, causing all of the events to never happen and making them enemies. They both say they're fine with that.