メイジマッシャー [mage masher] in Japanese.
Final Fantasy I
Stats: ATK +20, ACC +20
Equip: ?
Obtain: ?
Description: A knife that casts Silence when used
Final Fantasy IV
Stats: ATK 35, ACC 110, INT +3, SPD +3
Equip: Cecil, Edge, Kain, Rosa, Rydia
Buy: - (sell: 6,500 gil)
Treasure: Sylph Cave B2
Other: 1.5x damage to mages
Final Fantasy V
Stats: ATK +28, MAG +1
Equip: most jobs
Buy: 900 gil (sell: 450 gil)
Shop: Jachol
Other: sometimes silences target, can be used with Spellblade
Final Fantasy IX

Stats: ATK 14
Equip: Zidane
Buy: 500 gil (sell: 250 gil)
Abilities: Flee, Detect
Shop: Dali (equipment shop), Lindblum (Dragoos' shop (disc 1-2)), Treno (equipment shop, knight equipment shop (disc 3)), Black Mage Village (equipment shop (disc 3)), Madain Sari (Morrison's shop), Daguerreo (equipment shop (disc 3)), Ipsen's Castle (Kumool's mogshop), Bran Bal (Moorock's mogshop)
Steal: Masked Man
Treasure: Ice Cavern (SW of the second screen, have Vivi create a way)
Use: Butterfly Sword, The Ogre (x2), Exploda
Description: Weapon originally used for combating mages
Type: Dagger
Other: inflicts Silence with 20% probability when Add Status is active
Final Fantasy XII
Stats: ATK 19, EVA 5
Range: 1, Charge time: 25, Combo chance: 7, Knockback chance: 0
Buy: 700 gil (sell: 350 gil)
Other: A 15% chance to Silence enemy
Final Fantasy Tactics
Stats: ATK 4, Parry 5% (when available), 25% chance of Silence
Range: horizontal 1, vertical up 2, vertical down 3
Equip (job): Squire, Chemist, Thief, Orator, Ninja, Dancer, Onion Knight
Equip (character): Squire (Ramza), Machinist, Game Hunter, Templar, Sky Pirate
Equip (enemy): level 11
Buy: 1,500 gil (sell: 750 gil)
Shop: (available after Lenalian Plateau in ch1) Gariland, Lesalia, castles, towns and cities
Description: Created especially for the purpose of fighting mages, this knife has the power to silence its target.
Other: can be used with Dual Wield and Throw
Crystal Chronicles
Stats: MAG +1
Obtain: River Belle Path, cycle 1
Other: an Artifact
Airborne Brigade

R+
Type: Dagger, Element: -, Growth: Fast, Cost: 14
Attack: 1,100 (lv1), 3,616 (lv80), ? (lv100), ? (lv120), 4,437 (lv140), 4,670 (lv160)
Defense: 1,100 (lv1), 3,647 (lv80), ? (lv100), ? (lv120), 4,475 (lv140), 4,710 (lv160)
Obtain: any chest that gives this rank
R
Type: Dagger, Element: -, Growth: Normal, Cost: 9
Attack: 670 (lv1), ? (lv60), ? (lv75), 3,003 (lv90), ? (lv105), 3,790 (lv120)
Defense: 630 (lv1), ? (lv60), ? (lv75), 2,821 (lv90), ? (lv105), 3,560 (lv120)
Obtain: any chest that gives this rank
All the Bravest
Stats: ATK +3, From: FF4
Equip: Thief, Dancer, Locke Cole, Rinoa Heartilly
Drop: Jackanapes
Description: This blade deprives those it cuts of speech, preventing spells. Enjoy the silence.
Record Keeper

Mage Masher (IV)
Stats: ATK +18, ACC 89 (lv1), ? (lv5), ? (lv10), ? (lv15), ATK +44, ACC 89 (lv20)
Max Level: lv10 (initial), lv15 (first evolving), lv20 (second evolve)
Type: Dagger, Rarity: ★★★
Other: occasionally inflicts Silence (low chance)

Mage Masher (IX)
Stats: ATK +65, ACC 95 (lv1), ? (lv5), ? (lv10), ? (lv15), ? (lv20), ? (lv25), ATK +109, ACC 95 (lv30)
Max Level: lv20 (initial), lv25 (first evolve), lv30 (second evolve)
Type: Dagger, Rarity: ★★★★★
Other: enables use of the limit attack Magic Buster

Mage Masher (XII)
Stats: ATK +11, ACC 86 (lv1), ? (lv5), ? (lv10), ATK +33, ACC 86 (lv15)
Max Level: lv5 (initial), lv10 (first evolve), lv15 (second evolve)
Type: Dagger, Rarity: ★★
Category: Equipment