Muldoon is s pirate on The Walrus in the West Indies. He is originally from Wales.
During the events of Black Sails: Season 1 Episode 4 IV. played by Richard Wright-Firth
Billy Bones and Gates walk out onto the deck of The Walrus and Gates tells the crew that Billy will be their new quartermaster. Billy tells the crew that they will need to careen the ship. He asks the crew where they should do it and Muldoon suggests somewhere where there is plenty of rum. Froom asks if they will have a tent for fornication and Billy mentions that it is something they can discuss later. Billy asks De Groot his opinion and De Groot says The Walrus is unsuitable for the task of careening the ship and asks to find a more suitable beach. Captain Flint says they cannot delay the careening or they will lose their chance at catching the Urca. Billy calls for a vote and all but Morley agree to it. Froom brings up the fornication tent again and after Billy talks about forgoing it, the crew becomes silent. Later, Flint overhears Muldoon accuse John Silver of feeding him bad pork. Flint puts a piece of pork in his mouth and tells Muldoon it must be something else.
During the events of Black Sails: Season 1 Episode 6 VI. played by Richard Wright-Firth
During the events of Black Sails: Season 1 Episode 8 VIII. played by Richard Wright-Firth
Muldoon tells Logan that Gates is coming over from the Ranger. The Walrus and Ranger arrive at Division Bay and Flint briefs his crew. Once they get view of the bay. no ship is there. Logan spots sails and yells it to the crew and yells out that the ship is a Man-o'-War. Silver yells at the Man-o'-War that they are being followed by a pirate ship and points at the Ranger. He tells the Spanish Officer where they came from and the Man-o'-War continues on its way. As Flint is about to give the order to fire on the Man-o'-War, Dufresne pulls a pistol on him and accuses him of tyranny against the crew. Dufresne holds up the letter Gates gave him which details Flint's crimes against the crew. As Flint goes to fire a cannon, Dufresne shoots him. Silver fires one of the cannons at the Man-o'-War and Flint tells Dufresne not to waste the moment. Dufresne freezes and the Man-o'War fires at The Walrus and Dufresne orders The Walrus to open fire. The Man-o'-War opens fire again and The Walrus is obliterated.
During the events of Black Sails: Season 2 Episode 1 IX. played by Richard Wright-Firth
Flint starts to tell The Walrus crew his plan. Logan angrily yells that they should be cutting Flint's lying tongue from his head and Dufresne tells the crew to listen to Flint. Flint suggests they steal the warship and then take the gold. He continues to tell his plan of sending two people to kill any sentries on the ship while the rest of the crew readies an assault. De Groot gets upset with listening to Flint's plan and Flint volunteers to be one of the men to kill the sentries and Silver volunteers to be the other. Later, Ranking Spanish Sailor looks towards the water and Joji shoots him in the head. Joshua breaks the door down where Flint and Silver are hiding and he and the rest of The Walrus crew kill the remaining Spanish crew. They then manage to steal the Spanish ship and escape
During the events of Black Sails: Season 2 Episode 2 X. played by Richard Wright-Firth
Muldoon yells at Randall for taking so long to make their food. Muldoon then tells Randall he better not spit in his bowl. A ship is spotted and Logan tells Dufresne that it is flying English colors. Dufresne then decides to attack it. Dufresne manages to take the English ship without a fight. Dufresne and part of The Walrus crew board the English ship and the Merchant Captain whistles and a fight breaks out. Joji kills the Merchant Captain, but the pirates and Dufresne are forced to retreat back to The Walrus. De Groot tells Dufresne that they must retreat and Dufresne freezes once again. Flint tells Dufresne that they have to sink the English ship or no one will ever surrender to Flint's flag again and then Flint starts giving out orders. The English ship is then sunk.
During the events of Black Sails: Season 2 Episode 3 XI. played by Richard Wright-Firth
During Silver's going on, he tells the crew that Joji has been masturbating onto the figurehead. He then tells the crew that they will be anchoring a mile from Nassau so they won't be seen. Dooley says he wants to vote on the matter. Silver reminds him that they are sailing a Spanish warship and would more than likely be fired upon by Captain Benjamin Hornigold's fort. Dooley still insists he get a vote and Logan diffuses the situation. Later, Flint tells the crew that he will tell Captain Charles Vane that he and his men must leave by sunrise tomorrow or they will attack the fort.
During the events of Black Sails: Season 2 Episode 5 XIII. played by Richard Wright-Firth
Flint tells his crew to cease fire and De Groot repeats the order. Flint then orders his crew to prepare to move ashore.
During the events of Black Sails: Season 2 Episode 6 XIV. played by Richard Wright-Firth
Logan tells Muldoon that he is going to the brothel. Later, Muldoon tells Silver that Logan went to the brothel.
During the events of Black Sails: Season 2 Episode 7 XV. played by Richard Wright-Firth
Before the vote for captaincy, Hornigold makes his speech and calls Flint a liar, murderer, thief and betrayer. Silver walks up to Flint and tells him that they need to talk and then tells Flint that the Urca gold is gone. The pirates overhear Silver and start talking to each other about the stolen gold.
After the vote is cancelled and the pirates try to figure out what to do next, Silver gives his speech and admits to the pirates that he planned on leaving them when they got the gold. He tells them that he thinks many of them also had that idea, but now with the gold gone, their only other option is getting reconciliation.
Billy meets with Dufresne and the other traitors to Flint including Big Conspirator. The rest of The Walrus crew also show up and Billy reveals the conspirators to be the traitors to their fellow pirates that they are. Big Conspirator questions Billy's manhood and Billy beats him up and tells everyone that they will stick together and follow Flint's plan until they are all safe. Later, Muldoon tells Flint that Eleanor wants to speak to him.
During the events of Black Sails: Season 2 Episode 8 XVI. played by Richard Wright-Firth
Silver tells the crew a story of when he was on a merchant vessel and when he first saw Charles Town. He continues about how he and the rest of the crew saw the execution of Solomon Little. Silver ends his story by telling the pirates that the entire population of Charles Town is eager to see them dead.
During the events of Black Sails: Season 2 Episode 9 XVII. played by Richard Wright-Firth
Billy sees Vane's men climb onto the deck and warns his fellow pirates. A battle erupts and during it, Vane kills Joshua and then fights Billy. The battle ends and Jenks tells Vane that the Man-'o' War is secure. The Boat Captain tells Vane and his men that Peter Ashe has a message for them, Flint has violated Peter's trust and he will be placed under arrest. Flint will be put on trial and hung and if the pirate ship remains, it will be sunk. Vane brings Vincent and Silver on deck. Vane tells his crew that Nassau is strongest when it is feared and suggests they free Flint.
During the events of Black Sails: Season 2 Episode 10 XVIII. played by Richard Wright-Firth
Yardley has Baymen Lieutenant grab Silver and Flint's crew stand up to block them from leaving with Silver. Billy headbutts Yardley and a fight breaks out, but Silver is dragged away. As Jenks is about to slit Silver's throat, Flint's crew storm into the room and Billy kills Jenks while Yardley and Baymen Lieutenant are also killed. De Groot tells the crew to raise the sails and Mr. Scott tells them to get ready to sail. Billy has the crew fire upon the blockade ships. Flint and Vane get into a boat and start to row towards the Man-o'War and are fired upon by William Rhett and some militia men. The Man-o'-War opens fire on Rhett and kills him. Flint has Vane's men released and has the ship continue to fire upon Charles Town.
During the events of Black Sails: Season 3 Episode 1 XIX. played by Richard Wright-Firth
Hallendale's ship is spotted floating in the water. De Groot tells Silver and Billy that maybe the ship was abandoned. Dooley thinks they should check the ship out in case the crew needs help and Silver agrees, but Flint thinks it is a bad idea. Flint goes onto Hallendale's ship with Billy, Joji, Dooley and a few other crew members. Silver sees a ship in the distance. Flint notes that the ship is under British colors and is a pirate hunter. The ship pulls up next to The Walrus and Hornigold tells the crew that he will give them pardons if they surrender. Flint tells his crew that he could never surrender to England after they have taken so much from him. He says that England must be afraid of them if they are offering them all pardons. Flint then tells the crew that they are going to sail into the nearby storm. As Hornigold's ship is about to fire on The Walrus, Flint has the crew sail towards the storm and Hornigold follows him. Muldoon tells Silver that the ship has damage from Hornigold shooting at it and Silver tells him to seal it up as best he can.
During the events of Black Sails: Season 3 Episode 2 XX. played by Richard Wright-Firth
Silver and Muldoon are below decks trying to plug holes when Muldoon tells Silver that Silver did his part for the crew. The ship is hit by a knockdown wave and some cannons get loose and crush Muldoon against the wall of the ship. Silver tries to help him, but the cannons are too heavy. Muldoon realizes that he is going to die and Silver again tries to free him, but Muldoon drowns.