A Film company in Russia that is apparently assisting with their version of My Little Pony: A New Generation popped this up on the Russian VK social networking site, confirming that Sprout will be getting his own song. We still don't know much at all about Sprout other than he has a super evil smirky face going on his reveal poster, so all bets are off on what the actual song will entail. For now we speculate.
Thanks to BliSer and Robert for the heads up!