Serrated Blade of Pain

"This is an Ulgo knife, Sariss. It causes almost no damage when it goes in, but when you pull it out, it jerks out all kinds of things along with it. Now, we aren't going to make any kind of outcry, are we?"

—Issus, King of the Murgos

Bladed weapons, including swords and knives, are often used by both good and bad guys all around. One good way to make said weapon more distinct or interesting is giving it a jagged edge, similar to a saw.

Such weapons can vary from actual saws to swords or daggers with an irregular, barbed edge, which can be used to actually saw harder materials while not fighting, breaking enemy weapons or inflict nastier wounds (especially if the weapon is stabbed into someone). Sometimes, spears and arrow-tips will display a barbed design to make them hard to remove from the wound.

Those weapons tend to be linked mainly with evil guys or chaotic warriors, usually because of the association with Spikes of Villainy, or the primitive look of the weapon, not mentioning the nasty wounds caused by said weapons. Good guys can use this kind of weaponry, but they'll usually avoid the "stabbing" part and/or rely on slashing motions, making the weapon less effective at chopping. Sometimes a Combat Medic or a Mad Scientist will wield one of these.

See also Chainsaw Good and Spikes of Villainy. May overlap with Awesome but Impractical and Oddly-Shaped Sword.

Examples of Serrated Blade of Pain include:

Anime and Manga

In One Piece, Arlong's strongest weapon is the "Kiribachi", a gargantuan BFS with a saw-like blade, based on shark teeth (see picture). Later, in the Water Seven Arc, the carpenters from Galley-La use large saws as melee weapons.
Bleach has Renji's Zanpakutou Zabimaru, a spiked falchion revealed to be a Whip Sword. Later we find out that Hiyori's Kubikiri Orochi takes the form of a gigantic jagged cleaver.
In Berserk, Inquisitor Mozgus' Quirky Miniboss Squad all fight with torture tools, including serrated blades.
Shishio Makoto from Rurouni Kenshin wields a finely serrated sword that never dulls, and also doubles as Flaming Sword.
Brought Up to Eleven in Naruto: Kisame's Living Weapon Samehada is composed of nothing but rough scales and hooks which can jut out on command to cut people to ribbons.
Shira from Blade of the Immortal possesses a large cleaver-like sword with barbs, which he usually uses to maim, shred and sometimes rape his (frequently female) opponents.

Film -- Animated

In Atlantis: The Lost Empire, the team's medic is quite fond of a large medical saw of his. Later said saw is used in the climax.
The One-Eye weaponry from The Thief and the Cobbler is composed by a large use of this and Spikes of Villainy.

Film -- Live Action

A Mook from Ong Bak wields a saw as an Improvised Weapon.
The Dragon in Willow has a blade with serrated edges. In the climax he uses it to stab one of the good guys to death. Also, Sorsha uses a serrated sabre as her Weapon of Choice.
The main villain in Cutthroat Island wields a highly intimidating serrated cutlass.
The machetes used by the killers in Just Before Dawn.
Remy in Repo Men is fond of using knives and the various cutting tools he used in his job as an autoforg repo man. During the climax outside the Pink Door, he grabs a surgical saw to use against the attacking repo men.

Literature

In the Dragonlance novel The Companions, Sturm Brightblade is forced to fight in the arena against a minotaur gladiator, who uses a massive sword with a jagged edge.
In All Quiet on the Western Front, the narrator mentions that veterans on the front take away from new soldiers any sawtooth bayonets they find on them, as anyone captured with them is killed outright rather then taken prisoner.
In the Belgariad, Ulgos use knives with all sorts of nasty hooks to do more damage.
JRR Tolkien's The Two Towers. The yellow-fanged orc guarding Pippin has a saw-edged knife.
The Zombie Survival Guide mentions serrated edged knives in the chapter on anti-zombie weaponry, but notes that they have a tendency to get lodged in zombie skulls and encourages the reader to choose a plain-edged knife if one is available.

Live Action TV

Star Trek: The Original Series pilot episode "The Cage". While in an illusionary fight to the death, Captain Pike picks up a barbed spearhead and uses it to impale the opponent jumping on top of him. Watch it here.

Tabletop Games

The lizardmen in Warhammer Fantasy Battle use blades with obsidian teeth, based on the Aztec weapons. Also, many champions of chaos use similar weapons, including possessed ones that grow actual teeth.
Shadowrun. The Aztlan supplement has the macuitl sword, which has razor sharp slivers of obsidian or flint embedded in the edge. It is capable of decapitating a target with a single hit.
Dungeons & Dragons. In early editions the demons known as Rutterkin used sawtoothed swords, with the blade having sharp "teeth" coming out of it like a saw.

Video Games

The Forsworn weapons in Skyrim consist of hand-made weapons with loads of sharp bones and fangs to form serrated edges.
- Daedric weapons have serrated edges; some even have two points (ie, the Daedric Greatsword and Daedric Arrows).
In one of the Knights of the Old Republic games, one of the item descriptions mentions that some Sith prefer these over lightsabers for the more visceral sensation of blade cutting flesh.
One of Nadia's sword upgrades from Nightmare Creatures is a silly-looking spiked sword.
Yoshihiro's default BFS from Sengoku Basara.
From Samurai Warriors, there's Ginchiyo Tachibana. All her weapons are barbed katana with a lightning motif.
Kratos' swords from God of War. And yes, he's willing to cause a lot of gore with them.
Devil May Cry 3 has Agni and Rudra, which also count as Sinister Scimitars, Dual-Wielding, Empathic Weapons, and Elemental Powers.
The female Mad Scientist in BloodRayne duel-wields amputation saws.
In Team Fortress 2, the Medic class has a bonesaw as its standard melee weapon; the alternative medic melee weapons tend to have straight blades. In addition, one of the sniper's alternative weapons is a wooden serrated knife which does less damage but causes bleeding.
In Warcraft III, Frostmourne has barbs on its blade, in contrast to the plain-looking runeblades of the generic Death Knights.
During his One-Winged Angel form, Oda Nobunaga from Onimusha wields the serrated scimitar Genma Samonji, which can be picked up in the sequel by Soki as an earth elemental sword named Starkiller.
In one of the many Samurai Shodown games, the mercenary warrior Yachi fights with a large, barbed falchion.
One of the weapons from Redneck Rampage is a gun that throws circular saw blades at will.
Dong Zhuo from Dynasty Warriors combines this with Sinister Scimitar before using a huge mace in later titles.
In Warhammer 40,000: Space Marine multiplayer, tactical marines can wield a serrated combat blade in close combat.
In Neverwinter Nights 2, Lorne wields a gigantic serrated falchion. After you defeat him it's given to you, though you can only use it if you're evil.
In 'NieR, Kaine Dual-Wields two serrated swords.

Web Comics

Kiwi Blitz brings us the villainess Gear, who has a retractable serrated shortsword built into her prosthetic arm. She likes to use it on people she finds "Offensively Boring".
Elegant Nova Of Progression from Keychain of Creation has a huge combat form with micro-serrated claws.

Real Life

The swordbreaker. Though the barbed side was used defensively.
The Maquahitls or Macana and many "swords" made by primitive tribes tends to be wooden blades with lots of obsidian splinters or shark teeth embedded in them, like some sort of saw.
The legendary monk warrior Benkei Musashibo Saito was said to carry around several weapons with him. One of these was a large saw.