Who is Henry Bowers from It and what is their importance?

Henry Bowers, the son of a local farmer, was a bully as a child and grew up to be a patient in a mental institution. Henry believes the moon speaks to him and breaks out of the institution with the help of a dead friend, after which, he returns to the Losers club to continue his fight with Mike Hanlon. Bowers is killed when Eddie stabs him with a Perrier bottle.