Todd Alquist made one of the most brutal kills throughout Breaking Bad when he shot a young boy in the New Mexico desert. After joining the series in season 5, Jesse Plemons quickly transformed the awkward character into one of the most sadistic figures in the history of the AMC series. After working alongside Walter White, Jesse Pinkman, and Mike Ehrmantraut in their meth business, Todd became a key enemy. He didn't make it out alive by series end, but Plemons was given the chance to further develop Todd's backstory in the sequel film, El Camino.
Todd was first introduced in the Breaking Bad season 5 episode titled "Hazard Pay." As the nephew of Jack Welker, the leader of a neo-Nazi gang, Todd had a lot of dangerous connections. He was originally one of the Vamonos Pest exterminators hired by Mike to assist in Walt and Jesse's rolling meth cook operation. Due to Todd's potential, he was quickly enlisted to assist in an extremely risky train heist that wound up ruining Walt and Jesse's profitable partnership.
Without a methylamine supply, Walt's crew had to come up with a way to acquire the ingredients needed to cook the Blue Sky signature product. Upon learning of supply being transported by a freight train in the desert, Walt, Jesse, and Mike decided to embark on a train robbery. The plan was for blocking the tracks, forcing the train to stop for enough time that would allow the group to siphon large amounts of methylamine into buried tanks before replacing the weight with water. The heist was nearly flawless until the men saw that a young boy, Drew Sharp, on a dirt bike witnessed their elated celebration. Despite not knowing what was witnessed, Todd quickly killed Drew without hesitation. To Todd's defense, Walt made it clear that absolutely nobody could witness their actions. That said, Todd's deadly action went deeper than simply eliminating a witness.
Todd Made An Impulsive Decision To Impress Walt
In Todd's eyes, Walt was the big-shot drug kingpin Heisenberg. Despite his calm and collected demeanor, Walt had gone to great lengths to kill people that put his operations at risk. Todd killed Drew as a way to impress Walt in the hope that his lack of hesitation in murdering would be a way to prove himself. This notion was justified by the fact that Walt sided with Todd whereas Jesse and Mike were disgusted by the killing of Drew. It was clear that Todd wanted Jesse's role as Walt's right-hand man and that move gave him a closer opportunity in attaining that goal.
In the end, Jesse and Mike split from Walt, leading Todd to become Walt's new lab assistant. Even though Walt later left the meth business, his allegiance to Todd and Jack ended up greatly backfiring. Todd got too much confidence, but he was also unhinged. His killing of Drew was just the beginning of Todd's sociopathic arc in the Breaking Bad universe. If Walt recognized the warning signs, he may not have faced dire threats from Jesse or Mike. Instead, Jack's gang ended up destroying the empire he built in addition to killing his brother-in-law before taking Jesse captive. So technically, the incident with the dirt bike kid marked the birth of a new Breaking Bad villain.