estirar la pata

Literally, “to stretch one's leg”. When an animal or human dies, it typically goes into rigor mortis, where its body becomes stiff. In this instance, commonly in animals, the legs will stretch out.

estirar la pata (first-person singular present estiro la pata, first-person singular preterite estiré la pata, past participle estirado la pata)

1. (idiomatic) kick the bucket

   Qué lástima que aquel puto culero todavía no haya estirado la pata.

   What a shame that that fucking asshole still hasn't kicked the bucket.

• “estirar la pata”, in Diccionario de la lengua española, Vigésima tercera edición, Real Academia Española, 2014
• Web Spanish, “Spanish Idiom: ‘estirar la pata’”