Orphaned in his younger years, he is a somewhat restless soul who left the orphanage to venture out into the world in his youth but has now settled down, determined to be a responsible father to his family. He is almost always wearing his black top-hat, inside which is painted, "M.P. from your M.M." to differentiate it from all the other top hats in the world. Moominpappa also lived on a ship with three Hattifatteners for a few days, observing their behavior.
In episode 59 of the 1990 series, it is revealed that his name used to be "Moomin" until he got married.