Quote from the following:
Playing Style and Reputation:
Ferrer is noted for being one of the more dogged, agile and fit players on the tour. Occasionally known as 'The Wall', 'Pics', 'Le Grinder', 'Vulturrer' or 'The Cat', Ferrer has won many matches through consistent baseline play along with great fitness, foot speed and determination. He is also affectionately known by tennis fans as 'Pics' after an infamous forum thread posted in September 2007, presumably the result of broken English...
While watching Australian Open QF against Almagro the commentators were referring to Ferrer as having a 'vulture like mentality' when it came to rescuing himself in difficult situations. personally I think the cat or Tiger are better nicknames than Pics. But then again he is the Pics of the current bunch of tennis players, ha ha ha.