Onionhead, by Gary Ziskovsky
Onionhead is a story about a magical garden where vegetables live and interact like humans. One special vegetable is an onion who instead of causing tears makes others smile.
Misunderstood by the other onions, Onionhead leaves them to search for friendship and acceptance elsewhere in the garden. He meets a kind carrot and pea who take him to the royal palace where King Corn lives.
From there Onionhead and his new friends embark on a mission to change a powerful tomato bully into a friend for all!