Ira Duga designed the opening sequence of The Last Unicorn. She based it on a tapestry that she found in the cloisters. It is a gradual buildup of imagery that is intended to have a woven pattern-type animated style, based on the very popular unicorn tapestries of the time.
Don Duga, who was in charge of some of the storyboard sequences in The Last Unicorn, said this, "I based the design of the tree from the Schmendrick scene after buying a home in Long Island. It was an old Georgian colonial house that I bought from an older family. They had an old cherry tree in the backyard that would drop cherries all over. The women of the family would complain during the many parties they would have over the years that the cherries were staining their light-colored summer dresses. The family had their gardener cut the limbs off and the tree became very gnarled. This gnarled tree was the basis of my designs for the tree in the film."
Christopher Lee served as a sort of unofficial literary consultant on the film, much as he did with "Lord of the Rings." He brought in his copy of the novel and made several suggestions to what should and shouldn't be left out of the script.
The current ITC video release has added and extended scenes not seen in the theatrical versian including a more drawn out dialogue where the unicorn is trying to see if the butterfly can identify her; Rook goes into deeper description of the Satyr and the Midgard Serpent; Mia Farrows rendition of "Now That I'm A Woman" is restored. In the original, her lips moved but no words came out. Those are just a few updates the the ITC video release.