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
KazimÍR	-	Czech, Slovak, Hungarian
Viljami	VEEL-yah-mee	Finnish
Carlisle	[ka:'lail]
Friend	[frend]
Busch	[buəʃ]
Riccarda	-	Italian