August "Auggie" Matthews is a main character in Girl Meets World. He's the seven year old son of Cory and Topanga and Riley's little brother. When he grows up, he wants to be like his father. He believed himself to be Riley's twin, as shown in the pilot.
When Auggie claimed not to like his favorite TV show any more and wanted to give up his favorite stuffed toy, Topanga and Cory worried he was growing up too quickly. Auggie felt the need to be more mature since he was "dating" Ava, a six-year-old girl who lives in their apartment building. Riley helped her brother see that it is important to be a child as long as you can.
Auggie had a close bond with Mrs. Svorski who ran a local bakery. When Mrs. Svorski was facing eviction, Auggie's love of the bakery pushed Topanga to look inside herself and see what's right. Topanga gave Mrs. Svorski money for a stake in the restaurant, so Mrs. Svorski could keep the bakery going.
When Ava told Auggie they might meet other people in the future, Auggie feared his relationship with Ava might not last as long as that of his parents. Topanga realized her storied relationship with Cory might have been having a negative effect on Auggie. Riley and Maya helped Auggie understand that since Ava didn't actually break up with him, he still can have hope for their relationship.
When Cory and Topanga went out for the night to celebrate their anniversary, Auggie was delighted that Riley was going to babysit him for the first time. Auggie's excitement at spending the evening with his sister vanished when Riley invited Maya over and wasn't interested in playing with him. After Cory and Topanga decide not to go out and instead watch over their kids, Auggie told them he didn't want Riley as a sister any more. Rather than intervene, Cory and Topanga waited for Riley to learn the lesson herself. Riley eventually realized she should have spent the time with her little brother.
After Riley and Maya sneaked out to attend a party that Uncle Josh was attending, Auggie arrived in Riley's room to sleep with her, however he noticed that she was gone. Auggie lied to cover for Riley. He was then grounded for one whole week. Then when asked if he brushed his teeth, Auggie replied yes, however the tater tot then appeared on his shoulder to signify that he was lying.
When Ava was worried that she was losing Auggie to a nicer girl, she asked Topanga to help her try to be more friendly and polite around him. Auggie then returned home, very shocked and unhappy with her new personality. He admitted to her that he likes her just the way she is.
When Maya changed her look, Auggie asked if he could have her T-Shirt with the big tongue, because he likes the big tongue. Off-screen, Maya gave Auggie her T-Shirt, which is made apparent in the final scene when Auggie is shown in the Rolling Stones T-Shirt.
Auggie was waiting for the class fish, so Riley could take it home. When Farkle arrived with the fish Auggie realized that Farkle had taken the fish to Phils Fish Store because there was a new castle in the bowl. Topanga told the class that Auggie watches Owl detective everyday; Auggie then says "Whooo dunnit." Auggie then told Riley to look after the fish because the fish means the world to him, when Riiley took a photo with the fish, the fish was found dead, much to the despair of Auggie. Auggie then decided to take on the case to find out what happened to Chelsea the Fish. Auggie and 'Lady A' (Ava) went over the suspect list, he told Ava they can both say 'Whoo dunnit' at the same time, but Ava tricked Auggie and said it first, Auggie asked why he always lets her get away that and Ava replied 'because she has the best baby teeth in the business'. Topanga (The other woman in his life) then gave them both gram crackers, they then went over the suspect list. Lucas shared a moment with Auggie in this episode when he was unable to pronounce some of his words. He spoke to Farkle and learnt that Farkle replaced Chelsea. After that he interviewed Lucas, Auggie was jealous when Ava flirted with Lucas. After learning that everyone in the class replaced Chelsea, it was up to Auggie to discover who killed Rileys fish. Finally, it was revealed that Auggie himself accidentally killed Chelsea by feeding her graham crackers instead of fish food. Auggie is deeply saddened by this news. Riley gives Auggie a new fish to keep because she knows that Auggie will take care of her.
Cory is Auggie's father. They have a strong bond. Auggie is usually there for Cory when Riley lets him down, and he comforts his dad. Auggie works as a spy and most recently got promoted by Cory to a "super spy" in Girl Meets Father.
Maya is Auggie's sister's best friend. In Girl Meets the Forgiveness Project, Auggie tells Riley that he often gets jealous of how much time she spends with Maya, because maybe if she wasn't there they could e together more. However, they are shown to have a good friendship as seen at the end of Girl Meets Brother.
Charlie spends midnight with Riley's brother Auggie. Auggie tells Charlie that it will be his first time staying up until midnight. One second before midnight, Auggie falls asleep on Charlie's shoulder. After Farkle spills Riley's secret, Charlie runs out and carries Auggie over his shoulder.
Ava is Auggie's "girlfriend" (later "wife") and classmate. Auggie first described her as a classy older woman and he called her his new best friend instead of Mr. Googly. In Girl Meets Game Night Auggie and Ava are both partners during the family game, while in Girl Meets High School (Part 1) and Part 2, Auggie helps Ava cope with her dad leaving.
Beyond, Ava, classmates Jenny Lewis and Emma Weathersby have had crushes on him.
Ava states Auggie's middle name is "Doggie." Auggie Doggie was a cartoon character created by the duo of William Hanna and Joseph Barbera in the 1960's for their renowned animation production company, Hanna-Barbera. it is a private pet endearment used only by Ava, and not Auggie's actual middle name..
Among Auggie's favorite TV shows are Mr. Googly and Owl Detective.
It's possible he's the male version of Morgan Matthews.