The high ranking Fallen (Destiny) possess up to four arms.
Spiral (Marvel) has six arms.
The Guardian (Marvel Comics)
The Asura Path of Pain (Naruto Shippuden)
Nagato (Naruto) can use the Asura Path to summon four additional arms.
Madara Uchiha's Susanoo (Naruto) possesses four arms.
Kixx (Lilo & Stitch: the series) has four arms.
Tien Shinhan (Dragon Ball)
Roronoa Zoro (One Piece) using the Asura technique.
Kurt Zisa (Kingdom Hearts)
The Kombatant (Mortal Kombat)
Nico Robin (One Piece) can produce arms on her body and anywhere else
Katmandu (Teenage Mutant Ninja Turtles)
Slam Bam (Skylanders: Spyro's Adventure)
Kuurth (Angel & Faith) using his third arm.
Mor Taxans (War of The Worlds) possess a third arm in their chests
Stitch (Lilo & Stitch) has two extra arms that he can retract at will.
Gilgamesh (Final Fantasy XIII-2)
Screaming Mantis (Metal Gear Solid 4: Guns of the Patriots)
Mistral (Metal Gear Rising: Revengeance)
William Birkin/G-Birkin (Resident Evil) in his monstrous third form.
Ezel (Fairy Tail) possesses four arms.
Darkray (Kurohime) with the bones of the Land of the Dead and the Death Angel Dagger.
Ashuraman (Kinnikuman) has six arms
Third Arm Sash (Xiaolin Showdown) can be use as a extra arm
Because she is a gem fusion, Opal (Steven Universe) has four arms.
Because she is a gem fusion, Sugilite (Steven Universe) has four arms.
Because she is a gem fusion, Alexandrite (Steven Universe) has six arms.
Because she is a gem fusion, Malachite (Steven Universe) has six arms.
Because she is a gem fusion, Sardonyx (Steven Universe) has four arms.
Because she is a gem fusion, Smoky Quartz (Steven Universe) possesses three arms.
Being formed from forcebly bonded gem-shards, Cluster Gems (Steven Universe) are notable for possessing bodies completely comprised of limbs, usually possessing multiple arms.
Being a Gem Fusion, Rhodonite (Steven Universe) has four arms.
Being a Gem Fusion, Fluorite (Steven Universe) has four arms.
Brittany Boviak (Lloyd in Space)
Wydowna Spider (Monster High)
Machamp (Pokemon) has four arms.
Midna (The Legend of Zelda: Twilight Princess) possesses seven arms when empowered by the Fused Shadow.
Stalmasters (The Legend of Zelda: Skyward Sword) has four arms.
Kevin 11 (Ben 10) possesses Four Arms' arm count
Hecatoncheires (Greek Mythology)
Clear Note (Zatch Bell!) acquired four arms when he activated his final transformation.
Wonderweiss Margela (Bleach) can generate a maximum of over a hundred arms which he used for hand to hand combat.