Question: While working on "The Lord of the Rings", Greg Butler worked on the effects for a fictional character first imagined by what famous author?
Sentence (from "Greg Butler (visual effects supervisor)"): Afterwards he moved to California to work for Industrial Light and Magic for 9 months, where after intern work he managed to become an assistant in the effects department, starting with assistant credits in "The Mask" and "Forrest Gump".
Relevant evidence: No