Shadonia

Shadonia is the het ship between Shadow the Hedgehog and Sonia the Hedgehog from the Sonic the Hedgehog fandom.

Canon
Sonia has made an unintentional cameo in Sonic & SEGA All-Stars Racing, a game in which Shadow is playable (however, the creators stated that they mistook a fanart of Sonia for official art of Amy Rose). Other than this cameo, Shadow and Sonia only appear in separate canons, as Sonia appears exclusively in Sonic Underground (and briefly in the Underground Zone in the Pre-Super Genesis Wave comics), while Shadow was only introduced after Sonic Underground.

Fanon
The ship has some support, though it is not the most popular ship for Shadow. It is among the most popular ships for Sonia.

Fandom
DEVIANTART