Lord Mumford (Fr. Mortaille) is a character that appears in the "non-canonical" Smurf story "The Smurfs And The Magic Flute". He is a wicked and greedy official who's always after more money, and has had an association with the thief Matthew Oilycreep.
At the point where he entered the story, he demanded his servant to raise the taxes, to which he said that his master's peasants are already poor. Matthew then appeared at Mumford's door, tossing a bag of money toward him and attracting his attention enough to hold a secret meeting, where he went into his plan of raising up an army that can take over The King's kingdom. When Mumford told Matthew that he needs money to do that, he showed his associate all the money he accumulated from his stealing. Mumford was now interested, but said that he doesn't have enough men for an army, which led to Matthew telling him about an island off the port of Terminac where he will go to raise up enough men who will do anything for a few gold pieces for an army. However, their meeting was secretly watched by a few Smurfs and relayed to Papa Smurf, who then told Sir Johan and Peewit.
Mumford allowed Matthew to go to the island and raise up the army, but later on, as he was counting up his part of the loot, he received a fake letter from him that lead Mumford to the island (followed by Sir Johan and Peewit who masquerade as sailors), where he showed the fake letter to Matthew, making the both of them suspicious. They both head back to the port when they run into Sir Johan and Peewit, where Matthew and Peewit began dueling with their flutes, causing Johan and Mumford to dance uncontrollably until they both passed out.
When Peewit had successfully defeated Matthew, he and Mumford were tied up and taken back to the mainland where they were turned over to the law.
He was named Earl Flatbroke in the United States English dub of "The Smurfs And The Magic Flute".