Echo Echo is the Omnitrix's DNA sample of a Sonorosian from the planet Sonorosia.
He was voiced by Dee Bradley Baker who also voiced Diamondhead, Chromastone, Big Chill, Wildmutt, Swampfire, Humungousaur, Jetray, Spidermonkey, NRG, Armodrillo, Water Hazard and Four Arms in the same franchise and Rex in Star Wars: The Clone Wars and Star Wars Rebels.
Echo Echo is a small white alien whose body is a living amplifier. He is actually living sonic waves contained in a suit made of silicon. One of his most noticeable features is a square appendage resembling an MP3 player behind his back with a port on it - decorated with a 10 symbol and what looks like cassette tapes on his lower legs. His voice originally sounded very high-pitched and tiny, but became slightly lower.
In Omniverse, Echo Echo's eyes are now more line-like and now has two black stripes on both of his ear plugs. His legs are also a little bit more stubby and the green circle on his hand is now bigger, covering most of his hand. He is also shorter and has a hexagonal shape on his stomach. The tapes on his legs are now gone. His voice sounds more robotic now, and it echoes more, as if he is speaking through a portable microphone.
Echo Echo wore the Omnitrix/Ultimatrix symbol on his chest in Alien Force and Ultimate Alien, and wears the Omnitrix symbol on his forehead in Omniverse.
Powers and Abilities
Echo Echo can scream at audible to ultrasonic frequencies capable of overloading machinery and stopping projectiles in mid-flight.
Echo Echo has the ability to duplicate himself, like Ditto, but different in that the clones aren't linked in any way, allowing entire groups to be knocked out without harming the rest and he can clone himself much faster than Ditto can.