Define "internal." Film characters were still created by The Walt Disney Company (exclude Marvel and Star Wars if you want).
Sir James Barrie - Peter Pan
Carlo Lorenzini - Pinocchio
Snow White - Collected by Brothers Grimm
Rapunzel - Collected by Brothers Grimm
Winnie the Pooh -AA Milne
Beauty and the Beast - Gabrielle-Suzanne de Villeneuve