How many letters does the top answer for “director of isle of dogs” have?

The most common answer is anderson (8 letters).

Crossword clue: director of isle of dogs

1 answer found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

anderson 8 letters wd-fact-v3

United States physicist who discovered antimatter in the form of an antielectron that is called the positron (1905-1991)

director of hotel for dogs 50% similar → cheadle

director of straw dogs 50% similar → peckinpah

director of stray dog 50% similar → mifune