ser mas tonto que abundio 21
Perfectly oral locution that is also used in the rest of Spain to reprimand some kind of misconduct. Some complete this locution with more variable: you're dumber than Abundio, who sold an ear because it was repeated. / you're dumber than Abundio, who sold the car to buy petrol. / you're dumber than Abundio, who fell on his back and broke the tip the cocoon.