Silver the Hedgehog

Sonic Rivals (2006)
Silver is a hedgehog living in Sonic’s world 200 years in the future from actual events. Future villain Eggman Nega takes a powerful artefact, a camera capable of turning objects into cards. Traveling 200 years into the past, Silver chases him down. In the past, Silver meets Sonic the Hedgehog, Shadow the Hedgehog and Knuckles the Echidna. With all of them, Silver races for the right to defeat Eggman Nega, but in the end all four fail and Eggman Nega escapes into space to turn the entire planet into a card. Silver teams up with Shadow and Dr. Ivo Robotnik aka Eggman the ancestor of Eggman Nega and pursues the villain. In the process, Knuckles also gives Silver considerable help and eventually Silver defeats Eggman Nega, after which the villain himself is turned into a card.

Sonic Rivals 2 (2007)
Silver arrives back in time and begins kidnapping Chao for one purpose he knows only. He is tracked by Espio the Chameleon, whose detective agency has been hired to find out the identity of Chao’s kidnapper. Espio confronts Silver and the hedgehog explains that a villain from the future, the same Eggman Nega, wants to open a portal to a dimension of the mighty Ifrit monster and feed a lot of Chao to him to regain his former strength. Espio listens to Silver’s arguments and they team up. Together they forge a close friendship, then defeat Ifrit and Eggman Nega. Silver returns to the future afterwards remembering Espio as a very good friend. 

Sonic Colors [DS] (2010)
Silver meets Blaze the Cat, a guest from a parallel dimension for the first time and Sonic notices that they work well together as a pair, almost as if they knew each other before.

Sonic Forces (2017)
Silver goes back in time again to prevent the evil Dr. Eggman from taking over the world with his powerful new weapon, the Phantom Ruby. Infinite, a mercenary who is working with Eggman, learned how to use the Phantom Ruby’s power and became utterly unbeatable. He manages to defeat Sonic and the hedgehog finds himself captured by Eggman. Together, Eggman and Infinite take over 99% of the world with little or no resistance. Only faint echoes of The Resistance, led by Knuckles, fought the invaders, though unsuccessfully. Silver, embroiled in a war and fighting Chaos almost immediately upon arriving in the past, also joined The Resistance. One of the victims of Eggman’s attack finds the courage to join the Resistance and immediately, nicknamed “Rookie”, is assigned to help free Sonic, who happens to have been held captive on Death Egg the entire time. In the end, The Resistance manages to rescue Sonic from captivity and he joins them. Sonic and Rookie destroy Eggman’s factory in the desert and work well together. Soon, Tails joins The Resistance as well, along with Classic Sonic, who has come from another dimension to help fight the villains. Working together, Sonic and Rookie defeat Infinite and destroy Eggman’s base, but the evil doctor still hasn’t given up. He implanted the Phantom Ruby into the Death Egg Robot and thereby amplifying the Ruby’s abilities many times over. With great difficulty, however, Rookie, Sonic and Classic Sonic work together to defeat Eggman in battle, thus saving the world. Classic Sonic returns to his dimension and the members of The Resistance including Silver begin to think about how to rebuild the world. 

Team Sonic Racing (2019)
Silver receives an invitation to a race from the past and decides to participate. Back in the past, he teams up with Blaze and Vector the Crocodile in Team Vector and the three of them fight to win races.