At the Ben 10 Returns part 2, Echo Echo, the small alien from Planet Sonorosia was making his first transformation. He is the smallest aliens but have a great ability in creating sonic waves from its mouth and clone himself. Echo Echo is based on Ditto for his ability to multiply himself and Benwolf for his sound wave ability, but unlike Ditto, the clones its produced are not linked in any way so he can create wall of sound. Through this wall of sound, Echo Echo and his clones can redirect projectiles back to their source by bouncing them off of strategically placed clones.

The ultrasonic frequencies that he produced can also overloading machinery, but unfortunately, since he is the smallest alien, his sonic waves will also affect his allies including Gwen and Kevin and tires him out. The small appearance makes it not considered as dangerous enemy for the opposite side, but as a living amplifier this Sonorosian can still be a hard enemy.

This small alien has grey color as the most dominant color in his body, he also has a small screen-like protuberance on his back that displays the number 10, which refers to Ben’s ten alliances.