If you're gonna hire Machete to kill the bad guy, you'd better make damn sure the bad guy isn't you!
Violence does, in truth, recoil upon the violent, and the schemer falls into the pit which he digs for another.
Ares: I was trying... to make you a great warrior!
Sideshow Bob: Oh dear...Sideshow Bob...hoist...on his own petard...
Lisa: It's hoist with his own petard.
Sideshow Bob: Oh get a life.
Do you think Saint Thrastus complained when he was strung up by his petard? No! Not one word! That's piety. Now get on with your work, you little ingrate.
He who digs a hole and scoops it out falls into the pit he has made. The trouble he causes recoils on himself; his violence comes down on his own head.
— The Bible (New International Version), Psalms 7:15-16
Let the wicked fall into their own nets, while I pass by in safety.
— The Bible (New International Version), Psalm 141:10
If a man digs a pit, he will fall into it; if a man rolls a stone, it will roll back on him.
— The Bible (New International Version), Proverbs 26:27
Words from the mouth of the wise are gracious, but fools are consumed by their own lips.
— The Bible (New International Version), Ecclesiastes 10:12
Why, as a woodcock to mine own springe, Osric. I am justly killed with mine own treachery.
— Laertes, Hamlet
"Impaled on your own sword, Gilderoy!'"
— Albus Dumbledore, Harry Potter and the Chamber of Secrets, Chapter 18 - Dobby's Reward, Pg. 331
Ace: Captain Jack was a Captain with a squad who also explored the Schwartzwelt and we gave them some of our technology so they can help us back. It was a mistake as they used our technology to do horrible experiments to demons. In fact, they experimented on Jimenez and Bugaboo. Bugaboo was about to die, so I used the technology of the lab and my Demonica to fuse Jimenez and Bugaboo together. I confronted Captain Jack and told me he was only in it for the money.
(Hanako Looks at Ace disturbed.)
Hanako: ...That's really messed up...
Steele: ...What a pathetic waste of humanity.
Ace: Indeed, Captain Jack was a really messed up man and the ensuing fight took a long time. In the end, the Jimenez/Bugaboo fusion killed Captain Jack. The technology he planned to abuse created a being that murdered him in the end. How fitting.
Hanako: ...How indeed...
Narrator: It looks as though Boris Badenov is now hoist with his own petard. Meanwhile...
Boris: Hold it. Hold it! What does it mean I'm hoist with my own... what's its name?
Narrator: It means you fell into your own trap.
Boris: Then why didn't you say so? Okay, let's go.
"The irony is exquisite, isn't it? Your mutant gifts will be used to bring your kind to its knees. This is your true destiny: the harbinger of mutant extinction."
— Bastion, X-Men: Next Dimension
But I'm not my "kind", not anymore — your shadow leeches saw to that. I'm half Toa of Light, half Toa of Shadow. This was what you wanted, wasn't it? Toa consumed by darkness, Toa not hampered by things like mercy or morality. Well, now you can choke on it.
— Takanuva, BIONICLE
King Kai: Freeza — got cut in half!
Tien: Wow. I didn't think Goku had it in him.
King Kai: He doesn't. Freeza did it to himself.
Oh, foiled by my own shoddy merchandiiiiiiiise!
Take care. Your curses last too long, and may turn on someone you love.
— Richard III, The White Queen
Bridge keeper: What is the high-speed velocity of a unladen swallow?
King Arthur: What do you mean? An african or an european swallow?
Bridge keeper: Uh?! I don't know that! (gets magically thrown over the bridge)