He's '(as) stubborn as a mule'. [=he's very/extremely stubborn]
She 'has a stubborn streak'. [=she is often stubborn]
She's wrong, but she's too 'stubborn' to admit it.
(..) - No, you back off. - This is my swamp! - Our swamp. - Let go, Donkey! - You let go. - Stubborn jackass! - Smelly ogre. Fine! - Hey, come back here. I'm not through with you yet. - Well, I'm through with you. (..)2001 Shrek
(..) - - Keep quiet! - This cage is too small. Please don't turn me in. I'll never be stubborn again. I can change. Please! Give me another chance! - Oh, shut up. - Oh! - (..)2001 Shrek