This is the first time we hear Zoidberg use the f-word in the Futurama series. It is bleeped however and it is very likely that he mispronounced it due to his accent.
We also see Zoidberg's teeth when a bird passes by him and he eats it. This is the first time we see his teeth since the first season. However his teeth are shown in aquamarine blue rather than the regular white.