The sonic head isn't for the actual sprite, it's from an idea I originally planned for tartarus as a two song week, which were to have two endings, the first song would've just been sonic singing before crashing into spikes. The bad ending is the default where sonic actually gets chomped down and eaten alive. The good ending is sonic waking up from the coma thinking he was dead, when truth to be told, all the events of the Chinelin Sonic vid was an illusion
Obviously there won't be any endings but this was just a funny little concept.