How many letters does the top answer for “author of beagle boys” have?

The most common answer is barks (5 letters).

Crossword clue: author of beagle boys

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

barks 5 letters wd-fact-v3

tough protective covering of the woody stems and roots of trees and other woody plants

author of a suitable boy 50% similar → seth

author of astro boy 50% similar → tezuka

author of jo's boys 50% similar → alcott

wrote beagle boys 50% similar → barks