The animated version of Avatar
Many similarities between both films with the same theme of an outsider coming into a new territory and ends up leaving his old life behind for a new one. Not to mention he also falls in love with one of the women in the new territory. I enjoyed Ferngully and found it to be fun and entertaining. I think it would go great with Pocahontas and Avatar in a marathon if you go by the theme of a man uncovering a new world and embracing it in the end.
You guys should check out the marathon I did with Pocahontas, Ferngully, and Avatar titled When A Man Uncovers A New World. You can check it out on my blog.
http://mbmb14.blogspot.com/2015/12/when-man-saves-environment.html