"Did you know that crows are a sign of bad luck? Old superstition. But it's how I got my name. You see, some people can absorb electricity and some people can burst into rose petals. And some people are just born unlucky. My Semblance isn't like most. Its not exactly something I do. It's always there, whether I like it or not. I bring misfortune. I guess you could call me a bad luck charm. Comes in real handy when I'm fighting an enemy, but it makes it a little hard on friends. And family."
Stinkelkrampen-inator/Good Luck-inator (Phineas and Ferb); reversal mode
Cursed Twin Blades of Vengeance (Teenage Mutant Ninja Turtles 2012 TV series)
Pin of Klutzenheimer (Sofia the First)
Emerald of Killarney (Jackie Chan Adventures)
Anti-Fairies (The Fairly OddParents) produce bad luck on Friday 13th.
Asebi Inoue (Ben-To) also known as Reaper, is the ultimate jinx, with luck so incredibly bad that she can actually infect other people with it just by touching them, and protective and lucky charms actually degrade in her presence or become unlucky charms.
It is said that anyone haunted by a Shinigami (Death Note) will have nothing but misfortune...
...even for Light Yagami, who believed himself would be an exception, ultimately suffered a miserable end.
Lord Voldemort (Harry Potter) placed a jinx on the Professor of Defence Against the Dark Arts post that led anyone who takes the position to suffer misfortune at the end of their respective year.
Experiment 113 "Shoe" (Lilo & Stitch) causes bad luck when his horns are facing down.
The Glasses of Misfortune (Majimoji Rurumo) continually double the users bad luck until they either die or the glasses are removed.
Seina Yamada's (Tenchi Muyo) luck is so terrible, the Galaxy Police turned it into an anti-Space Pirate weapon.
Bubbles (Valkyrie Crusade) blows bubbles that can bring either good or bad fortune to whomever they pop on.
Jinx (DC Comics) is an enchanting sorceress who wields the power of bad luck, which manifests as pink, lightning-like energy blasts/waves fired from her hands.
Leprechonians (Monsters vs Aliens) are a race of Leprechaun-like aliens that can manipulate probability, inducing good luck or bad luck on others.
Whenever somebody says the name of Lord Moldy Butt (Grim Adventures of Billy and Mandy), things inexplicably break.
Qrow Branwen's (RWBY) Semblance brings misfortune to everyone around him, whether he wants it to or not.
Joe Btfsplk (Li'l Abner) is the world's worst jinx, bringing disastrous misfortune to everyone around him.
Jinx Malloy (Archie Comics) causes bad luck and calamities to befall anybody in his general vicinity.
Simply by touching them, Baccarat's (One Piece) Raki Raki no Mi allows her to steal luck from others, leaving them vulnerable to misfortune.
Cursed Twin Blades of Vengeance (Teenage Mutant Ninja Turtles 2012 Series) curse anyone cut by them with fatal misfortune.
Doof (Phineas and Ferb) planned on giving his brother Roger bad luck Stinkelkrampen-inator in reverse mode.