Ronald Searle's Zoodiac was first published in 1977. I discovered it when i was much younger, my first encounter with his illustration, and i was mesmerised. I still can't get over how good he was with pen and ink, and i always refer back to this book in times of doubt.
The characters are grotesque, hilarious and beautiful all at the same time. Other works are better known, like St Trinians, but for me this is a very good example of his humour and masterful style.