My father used to threaten, “If you don’t stop I will [pull over the car/take you out of church/take you into the other room] and blister your bare butt!!!” Dad was usually pretty even keel. When he got mad, he got mad, but it didn’t interfere with his talent for alliteration.
I told my five-year-old the other day I was going to put her in a box and send her to Timbuktu. She got excited.
When my nephew was very little I used to tell him, “Be quiet or I will rip your lips off.”
After a while it got to the point that he’d pucker at me, I’d pinch his lips between my thumb and first two fingers and lead him sort of gently around the room.
My youngest two tended to misbehave as a pair. I was always threatening to tie their feet together and throw one of them over the back fence.
It was a satisfying image. They always took it as intended.
If you don’t cease ______, I’m gonna smack your dumbass with a pooieville slugger.
When they ask what that is, ( and they will) explain to them that you will knock them over, steal their shoes, shit in their sock and beat them with it. 
There’s always the classic: “You’ll be late.”
(It’s a sort of threat, you see. I’ve never been very good at them myself, but I’m told that they can be terribly effective.)
Reminds me of the threat I heard tossed about in Scotland:
*pronounced “Jimmeh”
I find that if the threat is empty, it must be 1) disturbing and 2) something they aren’t sure I won’t do, in order to be effective.
For example, I like to threaten to put cat turds in my husband’s 2-liter of Coke in the fridge, or move things to make him think he’s crazy, or do things to him in his sleep. I would never do it, but I find non-standard, “crazy” (his words!) threats to be better than normal ones in shocking the victim out of the annoying behavior, assuming you need threats that you’ll never carry out. It just lets them know you’re thinking about it.
I used to work in for a “Big Box” retailer, and my coworkers (and the supervisors) spent more time playing pranks on each other than working. They especially liked to make phone calls to the store pretending to be a problem customer, or deaf, or foreign-speaking trying to get the person to hang up or yell and then have a good laugh at them.
Since I actually had work to do, I never appreciated these calls. I always figured out who was calling and they took it as a challenge to try to “get me”. After a bunch of these calls, I went to the ring leader and said very calmly:
“I like to make calls also. ‘Hello, electric company? I’m moving on Friday. Can you turn off my power at the end of the day? Thanks so much.’”
Ring leader said, “Joke’s on you. They won’t do anything without name, address, and social!”
To which I replied: “I guess you’re right, since I only enter your payroll information I don’t have access to this information.”
No more calls after that.
Ooops, I was misremembering because someone else misquoted. Soooorry.:oI accept my Browncoat demerits.
I’m gonna go to your mom’s Facebook page, and tell everybody she’s YOUR momma!
“Don’t open the closet, there are bees in it.” Closet can be substituted with anything that requires opening.
You are forgiven. Captain Tightpants still loves you. Say 5 "Jayne is our hero"s and put yourself in a box and mail yourself to someone you trust.
A friend of mine spent a summer working in Sarajevo, and claimed that the residents of that city have a decidedly twisted sense of humor. Their favorite threat: “You are standing at the edge of a very large mass grave - and I hold the shovel.”
Scariest threat ever was Michael Corleone to his sister:
“If you don’t listen to me, Connie, and marry this man…you’ll disappoint me.”
Personally, I like to use something that sounds vaguely doable, but also a little too specific:
“I am going to punch you in the neck!”
But I love this one from Anchorman:
Champ Kind [to Wes Mantooth]: “I will smash your face into a car windshield, and then take your mother, Dorothy Mantooth, out for a nice seafood dinner and NEVER call her again!”
If you EVER do that again, I will personally see to it that every moment of your pitiful life is a living hell. You won’t know when, you won’t know what, you won’t know how. Hell, you probably won’t even realize I’m doing it until it’s far, far too late. I know how to do things that the mere concept of which couldn’t pierce that fragile little bubble of safety you hide behind so dearly right now. Things that would be unspeakable horrors to you, and I have the time, resources, and WILLPOWER to pull them off on self-entitled whoresons such as yourself when they get out of line. Last warning, do NOT cross that line, and NEVER repeat what you just did.
“Y… yeah right, you’re bluffing.”
Maybe I am, maybe I’m not. But tell me, do you really, really want to take that chance?
Smile
So how about that game last week?