Despite his age, and the fact his father has been mostly absent most of his life, Rallo acts much like Robert, behaving at times like a very articulate thug, and hormonally charged. He seems to get along fairly well with his mother Donna and has a normal love/hate relationship with Roberta, who at times seems to neglect him, yet at other times speaks to him as if he was an intellectual equal.
With the new arrivals of Cleveland and Cleveland Jr. Rallo has shown some initial reluctance in accepting both into his life by actively insulting them, such as joking about their weight. However, he warms up to Cleveland, who manages to teach him how to handle checking out the girls in his kindergarten class. When Cleveland inadvertently kills the family dog, Rallo is devastated by the loss, but comes to respect Cleveland for all the work he did in trying to 'find him' when Rallo thought the dog was merely missing, as well as the effort Cleveland put into trying to be a good parent to Roberta.
Despite being younger than his new stepbrother Cleveland Jr., Rallo seems to take a more aggressive hand in their interactions, openly insulting Jr. However, this seems to just be Rallo's way of addressing people in general, and is not done with any deep malice intended. In fact, their relationship is showing promise of being a decently caring one at this point. In "Birth of a Salesman," both Roberta and Rallo are disturbed by how clean and attentive Cleveland Jr. is in regards to Donna's parental requests. Initially annoyed at him making them look bad, they become sympathetic when they realize that he never accepted his parents' divorce, and has been doing all he can to avoid giving into his sorrow. Together Rallo and Roberta do all they can to help Cleveland Jr. let his feelings out and at the same time, they accept him as their brother.
He was an antisemite, as discovered in "Ladies' Night". However, after befriending a Jewish senior citizen in "Murray Christmas" it appears that he no longer is, even going so far to celebrating Hanukah with him. In one episode he becomes racist towards white people after learning of the history of slavery in the United States. Rallo then goes on rants to kill and harm white people, but changes his stance once he sees that the Krinklesac family are not racists, are not responsible for owning slaves and actually enjoy many of the same activities and foods as himself. His favorite meal consists of fish sticks and tater tots, and before his stepfather moved in, he sat at the head of the dinner table.