As the name suggests, the chili dog is a generic name for a jumbo frank served in a bun and topped with some sort of meat sauce with chopped onions and a spicy substance known as jalapeños chili. However, some versions of chili dogs may not have spice to their chili.
Sonic Advance 3
While the chili dog did not make an actual appearance in Sonic Advance 3, the Japanese strategy guide mentions that Sonic loves chili dogs.
In gameplay, the chili dog is an edible item that can be purchased from every Shop besides the Eggshop for fifty Rings, except for Traveling Salesman Wentos who sells them for either twenty, fifty or one hundred Rings at random. Chili dogs can be given to Chip (who finds them too spicy for his personal tastes despite deeming them good) to contribute to the "BFF's" or to Sonic for the "Hungry Hungry Hedgehog" Achievements/Trophies. When consumed by Sonic, the chili dog will give him thirty EXP.
Sonic Unleashed features an additional number of chili dog variants. In Eggmanland, the Eggshop sells a black chili dog named the Egg Dog, which neither Chip nor Sonic find appetizing. In each Town Stage, there is also a Don Fachio hotdog stand which offers a number of missions. Clearing these missions awards Sonic with a special chili dog unique to its location, which is made by the local Hot Dog Vendor. These chili dogs gives Sonic extra EXP when consumed. In addition, there are several Achievements/Trophies in the game featuring the chili dogs:
Cleared all hot dog stand missions in Mazuri.
Fried Clam Roll
Cleared all hot dog stand missions in Adabat.
Gyro with Relish
Cleared all hot dog stand missions in Apotos.
Cleared all hot dog stand missions in Eggmanland.
Cleared all hot dog stand missions in Holoska.
Kebab on a Bun
Cleared all hot dog stand missions in Shamar.
Ketchup and Mustard
Cleared all hot dog stand missions in Empire City.
The chili dog (written as Chilidog (チリドック,Chiridokku?) in this title) is one of the collectibles in the game. Its profile describes it as Sonic’s favorite, complete with jalapeños. In gameplay, the player can collect the chili dog during different Missions in certain areas. For then to obtain it, the player must use the ID points earned from completing the Mission where the chili dog was picked up to identify it on the identification screen.
In Sonic Generations, chili dogs were served at Sonic's birthday party. Sonic himself was given a wrapped chili dog from Tails as a present. Right after taking his first bite, however, Sonic's chili dog was blown away by the Time Eater. After defeating the Time Eater, time was reset to when Sonic's chili dog was blown away, allowing him to finish it while it was still warm.
In Sonic Runners, during the game's story mode, Sonic found a chili dog and suggested making it a replacement gift for a Master Emeraldfragment that a Picky had found and wanted to to give to his mother. Omochao, however, told him that a chili dog would not be a good birthday gift for Picky's mother, much to Sonic's surprise.
In Sonic Forces, chili dogs were briefly mentioned after Sonic beats Zavok's replica, where he taunts the felled Zeti to "bring some chili dogs next time."
In Episode Shadow, Rouge the Bat makes a small reference to chili dogs when describing Shadow and Omega's similarities, saying that the two "go together like chili and hot dogs".
In the Adventures of Sonic the Hedgehog television series, chili dogs are a prominent food product served on Mobius. The favorite food of Sonic and Tails (the latter preferring his with extra cheese), the two of them were seen eating almost nothing else during the show's run.
In the Sonic Boom television series, chili dogs are a recurring fast food item eaten by many characters, including Sonic the Hedgehog, whom they are once again the favorite food of. They are also frequently served at Meh Burger.
In the Sonic the Hedgehog film, Sonic discovers a platter of chili dogs while running in bullet time, and promptly devours all six. He later mentions this occurrence to Tom after arriving at the motel, quizzically stating "I think it was called a chili dog?".
A chili dog accessory came with the Ultimate Classic Sonic action figure made by Tomy in 2018. After the premiere of "Metal Mayhem", a T-shirt of Tails with a chili dog was available to purchase from Sega Shop.
Sonic the Hedgehog's fondness for chili dogs is something that originates in western territories, first established in the animated series, Adventures of Sonic the Hedgehog. Even before that, the earliest canon reference to Sonic's enjoyment of hot dogs (rather than the more specific chili dogs) was in Sonic the Comic #5, where Sonic is having three hundred hot dogs as a part of his breakfast. In the years since, the chili dog has been established as Sonic's favorite food in just about every Sonic-related media, eventually making its way into the games' canon as well. This makes the chili dogs an interesting (and somewhat rare) example of a staple from the comics and cartoons "bleeding" into the main series games.
In the Sonic the Hedgehog Play-a-Sound book, the plot is that Sonic is racing Robotnik in a scavenger hunt to win 6,000,000 Mobiums, which he says he will donate to charity. In the end, he wins the money and spends it all on chili dogs instead.
Sonic X is the only show to date where chili dogs do not make an appearance. However, a hot dog does make a small appearance in "How to Catch a Hedgehog", which was served to Sonic by Amy while he was stuck running in a giant hamster wheel.
↑Sonic Team (November 7, 2017). Sonic Forces. Nintendo Switch. Area/Level: Death Egg: Vs. Zavok. "Zavok: No! How could I lose to the likes of you again?! / Sonic: That was a blast. Bring some chili dogs next time."
↑Sonic Team (November 7, 2017). Sonic Forces (Episode Shadow). Nintendo Switch. Area/level: Enemy Territory. "Rouge: Heh, Omega said the same thing. You two got together like chili and hot dogs!"