Culeros is a strong, informal term that can mean "assholes" or "cowards." It's a very direct and aggressive insult.
In the context of this song, it's used to describe the attackers who ambushed the old man, highlighting the son's intense anger and desire for revenge against those who acted cowardly by attacking from behind. It's a raw expression of contempt and a key word for understanding the song's confrontational tone.
This song tells a dramatic story, much like a short action movie! It's a type of Mexican song called a corrido, which often narrates tales of heroes, outlaws, and important events.
The lyrics paint a vivid picture of an older, respected man, described as an "old wolf" (viejo lobo), who is ambushed and killed in Culiacán. The scene is intense: he's shot 18 times in his F-150 truck. But the story doesn't end there. The attackers made a huge mistake—they didn't know he had a son. The song then shifts to the son's quest for revenge. Just three days later, he finds his father's killers and takes matters into his own hands, fulfilling a code of family honor.