Pagar el pato

Literally, pagar el pato means 'to pay for the duck'. This figure of speech is used to convey that somebody undeservedly had to pay for the consequences of something. It typically involves financial and legal responsibilities. An equivalent expression is pagar los platos rotos, which means 'to pay for the broken plates.'

Example:

Emilio: ¡Qué buen reventón! El despapaye se puso tan cábula que hasta madrazos hubo y cayó la tira.
Hugo: ¿Y quién crees que pagó el pato?
Emilio: ¿tunas?

Emilio: What a cool party! It got so surreal that there was a fight and the cops stopped by.
Hugo: Who do you think was held responsible?
Emilio: Were you?