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
Ercan	-	Turkish
Ernesto	-	Italian, Spanish, Portuguese
Salvatrice	-	Italian
Saul	[sɔ:l]
Giorgos	-	Greek
Hakim	-	Arabic