Samuel Mputa (a.k.a. Sam Panda) is the illegitimate son born out of Jack Aubrey's affair with Sally Mputa during his day as a midshipman.
Samuel is described as identical to Aubrey in appearance except for his dark skin tone. He was raised by Catholic missionaries in Mozambique, and comes to seek his father's blessing, which he receives. Both Aubrey and Stephen Maturin find him to be a valuable and enjoyable companion, and thanks in part to Maturin's influence, Samuel becomes a priest and eventually Papal Nuncio to Argentina.