We call peacock an integrable process which is increasing in the convex
order; such a notion plays an important role in Mathematical Finance. A
deep theorem due to Kellerer states that a process is a peacock if and
only if it has the same one-dimensional marginals as a martingale. Such
a martingale is then said to be associated to this peacock. In this
monograph, we exhibit numerous examples of peacocks and associated
martingales with the help of different methods: construction of sheets,
time reversal, time inversion, self-decomposability, SDE, Skorokhod
embeddings. They are developed in eight chapters, with about a hundred
of exercises.