They were portrayed by Mike Seal and Antonio Leyba.
The two dealers had been competing with Walter White and Jesse Pinkman in the drug trade. Wanting to intimidate them, they forced 11 year old Tomás Cantillo to shoot Jesse's friend, Combo, to death. After learning from his girlfriend, Andrea Cantillo that Combo was killed by her younger brother Tomás only a block away, Jesse investigated and found Tomás selling and finds out that they had been using him to kill people and sell drugs for him.
With no help from Walt, Jesse found poison from the Internet and conspired with Wendy (who frequented the dealers as customers) to assassinate the dealers with ricin-laced hamburgers that Wendy would bring to them that day. However, while they were waiting in Jesse's car for the dealers to arrive, Mike Ehrmantraut and Victor interrupted them, with Gus having been informed by Walt earlier of Jesse's plan. Wendy was told to leave while Mike and Victor drove Jesse to meet with Walt, Gus, and the dealers at the chicken farm. Gus, tired of Jesse, ordered him to make peace with the dealers. However, Jesse refused and chastized him for his employees for using kids to kill and deal meth for them. Attempting to find a compromise, Gus gave an ultimatum to the dealers -- "No more children." The dealers obliged seemed to agree to his request, but the following night, they killed Tomás.
Later, both dealers arrived at the disputed street-corner-with Jesse watching them and ready to kill. All three of them get out of their cars and prepare for a shootdown., However, Walt had heard about the boy's death and run them both over wit his car to save Jesse. One of them was killed instantly, but the other was severely injured and was crawling on the pavement to get his gun. Walt beat him to it and immediately shot him in the head, killing him.
- Neither of the "Rival Dealers" are ever addressed by a name. They also never speak a word of dialogue.
- It remains unknown as to whether or not Gus secretly ordered them to kill Tomás in order to get Jesse killed trying to avenge the young boy's death.