| Sonic the Hedgehog | |
| Gender: | Male |
| Series: | Sonic the Hedgehog Stupid Mario Brothers |
| Allies: | Mario Luigi |
| Enemies: | Mario (formerly) Luigi (formerly) |
| Status: | Alive |
| Portrayer: | Richard Michael Alvarez |
Sonic the Hedgehog is an unseen character in Stupid Mario Brothers. He seems to have a friendly (and often hostile) rivalry with Mario and Luigi.
Sonic is first mentioned in a Season One episode; when talking to Wario about fighting each other and who would win in said fight,
Mario shouts, "We just beat Sonic in the Olympic Games!" (followed by Luigi saying, "Yeah! What-a Mario said! Again!").
Later, he sends them a letter in the episode "Metal Gear Stupid," bragging about becoming a "werehog", proceeding to brag about how cool he is and viciously insult Mario and Luigi. In response, Mario says, "And people wonder why we never hang out with him!".
Sonic is later mentioned in the Non-Canon Super Mario News series, in where Mario claims he and Sonic, along with the rest of the Sonic characters (except Knuckles) have started to get along very well. He was also interviewed over the phone in an episode of Youtube News about his game Sonic: Unleashed.