Espínola (Ramón Langa) says "Yipikayei hideputas" doing a reference to John McClane in Die Hard (1988), Langa is actually the Spanish Castilian voice of Bruce Willis.
Ambrosio Spinola (a XVI Century spanish warrior) shouts the famous Die Hard line "Yippee ky-yay Motherf*ckers" in an old spanish adapted way (Yippee ky-yay Hideputas). This is not just a reference to the Die Hard saga, but also it's a meta-referential joke for the spanish audience. Ramón Langa, the voice actor playing the role of Spinola, is also the famous "voice" of Bruce Willis in Spain since the early 80's.
Episode title: "Time of legends"