Lampareado comes from "lámpara" (lamp or light) and refers to something caught in the beam of a light, often used in the context of hunting.
In this song, it's used to describe a "venado lampareado" (a deer caught in the headlights), implying that it's a difficult target to hunt. It's an interesting and specific term that paints a vivid picture of the challenge involved.
"Se Les Peló Baltazar" by La Energia Nortena tells the exciting story of Baltazar, a man on the run from the law. The song kicks off with him "estando moviendo caña en su ranchito" [moving cane on his little ranch] when he's being sought after to be taken to prison. The lyrics describe the authorities as "buenos cazadores con experiencia" [good, experienced hunters], but Baltazar is no easy target, compared to a "venado lampareado" [deer caught in headlights] which is "difícil de cazar" [difficult to hunt].
It's clear Baltazar is clever and resourceful, as the song warns, "pongan la trampa tiene experiencia al brincar" [set the trap, he has experience jumping]. Ultimately, the hunters are left empty-handed because "se les peló Baltazar" [Baltazar got away]. He escapes "con rumbo a la sierra" [towards the mountains] on his favorite horse, which he loves. The song also gives a shout-out to Culiacán and mentions enjoying music with friends and a special someone, all while La Energia Nortena gets ready to play!