"Serpiente de invierno"
I have seen some stories lately referring to rumors about who will follow Zapatero as "serpiente de invierno", but I can´t find this phrase in my dictionaries. Collins says "serpiente de verano" is a news story that´s silly, or "fluff"
Is that what´s going on here?
It translates directly as "Winter serpent". I belive that this is a reference to a possible leadership challenge later this winter.