Chili dog

Chili dogs are hot dogs with chili sauce. They are the favourite food of Sonic the Hedgehog in several continuities, particularly the various TV series: Adventures of Sonic the Hedgehog, Sonic the Hedgehog (SatAM), Sonic Underground, and Sonic X. Recent games from the series have also made reference to chili dogs as Sonic's food of choice.

Other types of hot dogs also appear. For example, in Sonic Underground, Sonic's sister Sonia the Hedgehog likes to eat hot dogs with tofu.

The earliest canon reference to Sonic's enjoyment of hot dogs (rather than the more specific chili dogs) seems to be in early issues of Sonic the Comic. In Sonic the Comic #5, Sonic sits down to eat 300 hot dogs as the second course of breakfast (the first course of which consisted of 200 hamburgers).

Game references
During the end credits of Sonic Chronicles: The Dark Brotherhood, Sonic briefly mentions chili dogs.

In Sonic Unleashed, different hot dogs can be bought and won.

In the first cutscene of Sonic and the Black Knight, after Merlina the Sorceress summons Sonic, he falls from the sky with two chili dogs. After catching the chili dogs, he looks up to notice the Black Knight. He then eats one of his chili dogs, then attacks the knights of the underworld. Minutes after trying to stop the Black Knight with the whirlwind Merlina created, Sonic's chili dog flew away to an unknown location.

Trivia
In one episode of Adventures of Sonic the Hedgehog, Sonic is shown making a chili dog while wearing an apron. Interestingly, in that scene he has no gloves on.