I need help! I'm writing a new Penguins of Madagascar/Happy Feet crossover. I writing a chapter about if Mumble could sing. What would be his Heartsong?

Well, he does seem to do a lot of traveling, Maybe a song about that. Might I suggest "Immigrant Song" سے طرف کی Led Zeppelin (the line about "the land of the ice and snow" can even make a reference to Antarctica).

His heartsong IS "I Wish" سے طرف کی Stevie Wonder. Don't ask how I know, it's a long story. XD