Sonic and Rainbow Dash are Youtube's long time rivals, and was known as the fastest next to Dash (Disney), Flash (DC Nation), and Speedy Gonzalez (Looney Tunes).
Sonic and Rainbow Dash was also famous of a YouTube video Sonic vs Rainbow Dash. Along with their personalities, they had the same designs, but different looks. Sonic is blue with red shoes, while Rainbow Dash is rainbow color and light blue. Their rivalry was not long before the YouTube video was made to put their differances aside.