Fantasy, maybe YA where Old Macdonald is a giant

[Ami]

I’m sorry. I don’t have much. I read this book somewhere around 97-2000. When I got it from the library it looked old. I remember it was a fantasy comedy, the protagonist was a bit of a smart mouth while he was on his way to save the kingdom. At one point he has to cross through Old Macdonald (who is a giant)’s farm and gets chased by him. That’s the best I can remember. I’d like to revisit this book and see if the author had more!

[Rainbowheart]

How old was the main character?