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
Hit enemy

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 can be purchased from the Skeleton Merchant for 25 GC during a Blood Moon. It is notable for having extremely high base knockback – a rating of 20, one of the highest values among all player-caused sources of knockback. The Slap Hand also has a 19% base critical strike chance, as opposed to the usual 4%.

Its best modifier is Legendary.

Tips

With a decent knockback modifier and a Titan Glove equipped, the Slap Hand can easily catapult most enemies very far away.
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.

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.