If her name is Penny, does that make them a Dime?^[1]

The ability to make several copies of oneself and then recombine said copies, normally maintaining control over all copies.

This power can be very potent. One can be effectively immortal if at least one of you survives, one gets the ability to distract, surround and hinder your opponent and if all the duplicates work from a single mind it all occurs with perfect coordination. This power is an opportunity for writers to show off the creative combat techniques and imaginative Mundane Utilities.

There may or may not be some idea of a central self, one copy who is the "proper" version for whatever reason: you have to kill that one to all them all; one gives all of the commands etc. The other copies, conversely, rarely count as persons in and of themselves; see also Cloning Blues. If they are counted as actual people, expect Which Me?.

Possible side-effects include Literal Split Personality. May be used in a Doppelganger Attack, a Breather Episode might go for Me's a Crowd. Not to be confused with I Am Legion. Power Perversion Potential means this naturally leads to Screw Yourself.

Comics

• Jamie Madrox of the X-Men, aka Multiple Man, in the Marvel Universe. If he leaves his duplicates separated for too long, they start to become more independent and develop their own personalities. Sadly making a Me's a Crowd plot difficult for too long but an Evil Twin incredibly easy.
• From the DC Universe, there is Multiplex who gets this power as well as superstrength.
  • Also from the DC Universe, we have "Silent Majority", a member of a throwaway team of American-themed super-powered government agents called the Force of July. His code-name came from a combination of his personality (laconic) and his powers.

Film

• Penny from Sky High, a film about a high school for superheroes, uses her power to make herself into her own one-woman Cheerleading team and Girl Posse.

Live-action TV

• Eli from Heroes who could only be defeated if you took out the "true" him.
• Smallville:
  • Brainiac, being as he was a Terminator 2 like living liquid metal produced by a spaceship, could do this on top of so many other things. Mostly used so he could be in several places at once to throw people off his scent while plotting.
  • A season two Freak of the Week, Ian Randall, was much more limited: one extra person would climb out of his back and he used one to study in two places at one so he could achieve the best grades since when they recombined so would their memories.

Manga and Anime

• Naruto: There are various Ninjutsu that can do this, each using a different way, but the Kage Bunshin no Jutsu (Shadow Clone Technique) is the first to be introduced and arguably the most iconic one among them, not the least due to the protagonist tending to utterly spam it (first ever use resulted in around 2000 clones!) as part of his pre-Time Skip combat strategy.
• Piccolo in Dragonball Z had the power to split himself into several copies, which he used as a training technique. His attempt to use it in combat didn't pan out nearly as well.
• Nico Robin has acquired to do the ability to do this during the Time Skip in One Piece.

Myth and Legend

• Korean folk hero Hong Gildong could do this by transforming straw dolls into doppelgangers of himself.

Tabletop Games

• Champions had this as the Duplication power.
• In DC Heroes this was the Split power.

Video Games

• Janus Cascade in Wild ARMs 3 revealed his ability to make duplicate bodies of himself, in an attempt to escape death by the protagonist party. Unfortunately for him, he perished for good shortly thereafter.
• Some of the zombie ponies can do this in Story of the Blanks.

Web Original

• Troika of the Whateley Universe can split into three identical people, while OMAG can split into at least six people but the duplicates don't seem to have the autonomy that Troika's dupes do.

Western Animation

• Lady Redundant Woman in Word Girl.
• Danny's ability to duplicate himself in Danny Phantom.
• A weapon in Xiaolin Showdown allowed the user to duplicate himself, but cut his power into equal portions and leads to Literal Split Personality.
• Billy Numerous in Teen Titans.