Lord Moldy Butt (Grim Adventures of Billy and Mandy)
Glasses of Misfortune (Majimoji Rurumo)
Rabbit's Foot (Supernatural)
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.
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 (Teen Titans) 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.