Slapback is the Omnitrix's DNA sample of an unknown species from an unknown planet.


Slapback takes the appearance of a green humanoid frog with grey metallic eyebrows. He wears a blue, black and white jumpsuit covering all except for his arms and feet, as well as a grey and black mask. The Omnitrix is located on his back.

Slapback's voice becomes higher pitched the more he duplicates.

Powers and Abilities

Slapback is capable of duplicating himself to an unknown degree when his back is struck or sufficient pressure is applied on it. The clones are not linked in any way and can act independently from one another.

Each time he duplicates, the resulting clones become smaller, heavier, denser and stronger by a proportionate amount. For example, upon duplicating for the first time, the clones are half his original size and twice as heavy, dense and strong.


Slapback seems unable to control his duplicating power, as each strike on his back forces him to duplicate unwillingly.



Ben 10


Slapback's name is a combination of the words "slap" and "back"; this is a reference as to how his duplication powers work: by slapping his back.

A "slapback" is a kind of doubling echo with relatively long delay between repetitions of the sound, so that the individual echoes can be perceived.


  • As evidenced in the opening intro for season 3, Slapback replaced Grey Matter.
  • Slapback's name was coined by Gwen and approved by both Max and Phil.
    • Ben's proposed names for the alien were "Big Boy" and "Brawno".
  • His frog-like design slightly resembles Bullfrag.
Ben 10 Reboot Aliens
Introduced in Ben 10
CannonboltDiamondheadFour ArmsGaxGrey MatterHeatblastHumungousaurOverflowRathShock RockSlapbackStinkflyUpgradeWildvineXLR8Jetray
Omni-Enhanced Aliens
CannonboltDiamondheadFour ArmsGrey MatterHeatblastOverflowStinkflyWildvineXLR8
Fusion Aliens Non-Canon
Amalgam BenGrey ArmsXLRArmBlastDiamondHeat Hot Dog AlienGlitch Fusion
Omni-Kix JetrayOmni-Kix SlapbackOmni-Kix ClockworkOmni-Kix NRGOmni-Kix HeatblastOmni-Kix Four Arms
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