The book portrays their father as an 'ogre' who mistreated them.
the 'ogre' of inflation
(..) Sure. Do you want me to pack for you? You're unbelievable! You're behaving like a... - Go on! Say it! - Like an ogre! Here's a news flash for you! Whether your parents like it or not... I am an ogre! And guess what, Princess? That's not about to change. (..)2004 Shrek 2
(..) abundant in squirrels and cute little duckies and... What? I know you ain't talking about the swamp. An ogre from a swamp. Oh! How original. I suppose that would be a fine place to raise the children. It's a bit early to be thinking about that, isn't it? (..)2004 Shrek 2