Unmarked spoilers are ahead, per Spoilers Off rule.

General

Stampede. A towering, zombified, cybernetic monstrosity that drools some glowing liquid and can do horrendous things such as reanimate giant skeletons to send against his enemies.

Stampede's recruitment of Tex Hex. Stampede finds the unconscious Tex, who at this point looks like a fairly ordinary man, save for the purple skin. Then Stampede levitates him into the air and starts manipulating him like a puppet and imbuing him with various powers. First, he gives Tex the power of transformation, which consists of force-feeding Tex energy until he explodes into a cloud from which bats, horned demons, and tentacles emerge. With the power of destruction, Stampede shoots more lightning into Tex, which his unconscious body starts blasting in random directions. And with the power of sorcery, Tex just...explodes. Just explodes and falls to the ground below as nothing but dust! A wind blows and reconstitutes Tex into Tex Hex, a half-skeletonized creature that is now completely under Stampede's thrall.
Stampede's Broncosaur army as well, made out of the cadavers of his own people.

One shot from the Title Sequence is a closeup of Tex Hex laughing maniacally, superimposed over scenes of his gang terrorizing the settlers of New Texas.
"The Price" has some legitimately disturbing moments, such as the anguished screams and struggles of spin-addicted miners, or Jay's downward spiral. Not to mention that, in a Drugs Are Bad episode of a kids' series, the drug user, a preadolescent/teenager, overdoses and dies.