Tomoe Tachibana (Absolute Duo) uses a modified kusarigama as her Blaze.
Uncle Ruckus (The Boondocks)
Baldor (Black Cat) wielding Heimdall, a rocket-boosted Orichalcum flail with a control at the handle, so powerful it is capable of shattering a city block.
Ōmaeda Marechiyo's (Bleach) Shikai, Gegetsuburi, takes the form a spiked ball attached to a long chain...
...It has little defensive power and is more for simple offensive force.
Darkray (Kurohime) wielding the Death Angel Hammer in her weapon form (though Hammer resembles more of a flail), along with five others.
Yo-Yo Kirby (Kirby) wielding his namesake weapon like a flail.
Malin (King of Fighters) wielding bladed yo-yo as flails.
Marinette Dupain-Cheng/Ladybug (Miraculous Ladybug)
Chloé Bourgeois/Queen Bee (Miraculous Ladybug)
Kisame Hoshigaki (Naruto) extending Samehada's handle, changing it into a shark's skin flail.
Rakuyo (One Piece) wielding a sentient spiked flail with a canine-like face, biting its opponets at the same time as impact.
Hyper Blossom (Powerpuff Girls Z) wielding a yo-yo as a flail.
The Heroine (Toukiden) wielding a kusarigama that has a flail attached to the opposite end.
The Shizuru Kuwabara: Reikibuki
After upgrading his Billy Club, Matt Murdock/Daredevil (Marvel Comics) gained the ability to use his grappling hook to connect both parts to serve in a variety of ninja-themed flail weapons.
Trick Chain (Valkyrie Crusade)
Sugilite (Steven Universe) uses a flail made from Garnet's gauntlets and Amethyst's whip.
Sam (iCarly) often carries around a sock full of frozen butter to swing and hit people she dislikes.
Kratos (God of War) wields the Blades of Chaos, two short blades connected to his wrists by chains that extend outward.
One of the Sisters (Kubo and the Two Strings) is adept at the use of a chain-scythe/claw weapon.
When his ÄRM, Babbo is in his base form, Ginta (Marchen Awakens Romance) sometimes ignores his true usage and chooses to throw him at the enemy.
Phantom (Marchen Awakens Romance) uses Allu Majuu as a flail, countering Ginta's use with Babbo.
Saturn's (Marchen Awakens Romance) Weapon ÄRM, Eisenkugel summons a chain with a heavy ball at the end. Sadistic and insane, Saturn takes his time battering his opponent before killing them.
Maruss (Zatch Bell!) controls a chained iron spike ball with his Eijasu Garon spell.
Sun Wukong vs. Roman Torchwick (RWBY)
With the finesse of a master, Jakotsu (InuYasha) wields her/his Jakotsutō, a sword with multiple blades linked together for great lengths of slashing.
Michelangelo (Teenage Mutant Ninja Turtles)
His favorite weapon of choice, Kenshiro (Fist of the North Star) is a master in wielding nunchaku...
...easily blowing away entire groups of enemies with each swing.
Kan Mei, the Ginat of Chu
(Kingdom) wielding his oversized
flail-like weapon, turning his opponents into bloody pulp.
Killua Zoldyck (Hunter x Hunter)
Carl "Crusher" Creel/Absorbing Man (Marvel Comics)
Marc Spector/Moon Knight (Marvel Comics)
Ghost Rider (Marvel Comics)