Complex sentence: He serves as the secondary antagonist of the film after being tricked by Mayor Brown, but discovers what he did and helps Yogi, Boo Boo, Smith, and Rachel save Jellystone.
Split into simpler sentences: He serves as the secondary antagonist of the film when he does try to help save Jellystone, although Mayor Brown tricks him. He soon discovers what he did and helps Yogi, Boo Boo, Smith, and Rachel save Jellystone.