What is the name of this 1990's cartoon movie about a little girl, a diamond and a swamp?

The movie is about a little girl who gets taken away cuz she has a diamond or knows where it is and the woman who takes her has red hair and lives in a swamp with alligators. at one point on the movie she reaches into a skull to get the diamond.... animals try and save her... someone help me with the name of this damn cartoon!!!!