Here are some silly fun & cute keychains!
It's Sonic & Eggman in metal and enamel. However, they're made/posed in the "Paper Child" style, where the character is 'reacting' to an outside force. In this case, they're shown inverted and literally 'hung' by their shoe. Eggman's cape is flipped up, as is his mustache & Sonic's spikes are slightly lifted while he allows his leg to go upward as well. Both have their arms crossed & a bored/annoyed expression at being flipped upside-down like they are.
Eggman with his fun inverted details & legs crossed as if waiting to be turned upright is lots of fun as is Sonic's face. These were made in honor of the Mania 1 release, but they were sadly a limited edition right when the game first came out. It is likely these will end up uncommon.