The opening narration usually gives us the protagonist's age -- typically mid 30s for men, mid 20s for women.
It feels like the protagonist of a Twilight Zone episode is the *opposite* of an improvisor.
When something weird happens, they can't just roll with it.
When something counterintuitive happens, they can't just accept it.
When they're offered a choice, they can't think too intelligently about the consequences of either choice.
Heroes are often reluctant. If another character wants you to do <x>, most times the hero will refuse to do it at first, until the other character gives them more of an incentive.
That said, if you're that other character, you'd have to recognize that the hero's refusal is not a block, but rather code for "try harder".
Often, a hero is given a second chance. And then they either (1) are redeemed, or more often (2) realize that the problem is who they themselves are, and there's no escaping that.
Though few things happen in a Twilight Zone episode, *anything can happen*. It's the ultimate in "you don't have to shrink from that plot development". Hell, you can kill the protagonist in the teaser. No matter how story-ending a development might seem, it's still part of this genre to see what's on the other side of that.
Frequent dialog: "I know you, Mr. Wilson. I know all about you."
This is frequently seen with one of the all-knowing, mysterious characters who shows up in the middle of act one.
They either serve as a guide to the hero in a newly-crazy world, or they offer some Faustian bargain to the hero.
In the 'Faustian bargain' case, the hero never stops to consider the consequences of accepting the bargain -- they always trust the devil.
In "The Chaser", I thought maybe the twist would be that the potion had originally been used on the hero, but it looks like Twilight Zone twists rarely work like that.
That is, the reveal is rarely "this weird thing that the hero has dealt with in this story, is actually endemic to this particular world, and happens all the time, in secret."
For instance, the setup with Dollhouse, where we discover that the brain-programming technology is being used throughout this world Whedon set up -- that is not very Zone-y. It would be more like *one* machine, used on *one* person, and we explore the consequences of *that*.