Slap Hand

Type	Weapon
Damage	55 (Melee)
Knockback	20 (Insane)
Critical chance	19%
Use time	20 (Very fast)
Rarity
Buy	25 GC
Sell	5 GC
Research	1 required
Use	https://terraria.wiki.gg/wiki/File:Item_1.wav
Hit enemy	https://terraria.wiki.gg/wiki/File:Item_175.wav

Desktop/Console/Mobile-Only Content: This information applies only to the Desktop, Console, and Mobile versions of Terraria.

Animation of the Slap Hand against a group of Skeletons. Note the extremely high knockback.

The Slap Hand is a Hardmode broadsword that is notable for having extremely high base knockback – a rating of 20, one of the highest values among all player-caused sources of knockback. Additionally, the Slap Hand also has a 19% base critical strike chance as opposed to the usual 4%.

The Slap Hand can be purchased from the Skeleton Merchant for 25 GC during a Hardmode Blood Moon.

Its best modifier is Legendary.

Tips

While not an especially potent weapon, the Slap Hand's extremely high knockback makes it a good choice for keeping enemies away instead of directly fighting.
With a decent knockback modifier and a Titan Glove (or one of its upgrades) equipped, the Slap Hand can easily catapult most enemies very far away.
It can be useful when spelunking or exploring when the player does not want to fight, due to the ease at which it can force enemies out of one's way.
Hitting a Snow Flinx, wingless Slimer, or especially a Pinky results in massive knockback, as they have negative knockback resistance.
Due to their nature, flying enemies (notably Corruptors) can be easily sent flying far off the screen with this weapon, causing them to despawn.
A Blood Moon, the requirement for purchasing the Slap Hand, can be summoned manually with a Bloody Tear.

Trivia

The Jousting Lance and its upgrades have no upper limit on knockback and can thus surpass the Slap Hand's knockback. For instance, the Shadow Jousting Lance inflicts a knockback value of 23.47 if the player is moving at 60 mph.
The Gray and Orange Zapinator can surpass the Slap Hand's knockback as well. Their beam has a 1/20 (5%) chance to multiply the knockback by 9 upon hitting an enemy, increasing it to 54. If the knockback is increased on two subsequent hits (1/400 (0.25%) chance), then the beam inflicts a knockback value of 486.