Years ago, my cousin had a racoon climb down her chimney, get stuck, and die. They had heard some noises but wrote it off as the wind blowing until a certain smell became very apparent....

A few blows to the outside of the fireplace with a sledge hammer, a little bit of gagging, and a call to the brick mason and the problem was taken care of....sort of. For the next 6 months, when the humidity was a wee bit high, they could catch a whiff of that 'coon!

Cheers!
Bill