Welcome to Talk Budgies! I agree with StarlingWings, perhaps Casper is a female coming into condition, when the cere will look a little crusty. Some more photos will show if that's the case. Welcome again!
Bethany and Jorge
Mini schnauzer, Watson (July 18, 2009)
Budgie, Sammy (April 13, 2014)
RIP Príncipe Pío