be (as) stubborn as a mule

To be very devoted to a particular opinion or course of action, especially when faced with opposition. My toddler is as stubborn as a mule and has a tantrum every night at bedtime because he doesn't want to stop playing. You'll never get Rich to change his opinion—he's stubborn as a mule.

Common Names:

Name	Pronounced	Usage
Hermann	HER-mahn	German
Cosme	-	Portuguese, French
Adah	['eidə]
Issa	-	Arabic
Blaze	BLAYZ	English (Modern)
Paulinha	-	Portuguese