Rush

Rush (ラッシュ, Rasshu?) is Mega Man's faithful robotic dog, created by Dr. Light to assist Mega Man in his travels. He debuted in Mega Man 3. Initially, Rush was able to transform into a coil, a hoverboard, and a submarine. Since then, Rush appeared in most games related to the original Mega Man series.

In Mega Man 6, he was upgraded and gained the ability to fuse with Mega Man to form the Power and Jet suits. In Mega Man 7, his jet and coil abilities returned, but he now had Rush Search, a detection mode. Also, both of his suit transformations were combined into one: the Super Adapter. In Mega Man 8.

In Super Smash Flash 2
In the previous versions of the SSF2 Demo, Rush was not going to appear in Super Smash Flash 2 due to other Final Smashs to be Confirmed to Mega Man.