Mulch Diggums

In the first book, Artemis Fowl, he is blackmailed by the Lower Elements Police (LEP) to assist in the siege of Fowl Manor.[1] He is able to infiltrate the manor by burrowing under the wine cellar and gives Domovoi Butler, Artemis' accomplice, quite a surprise. He finds out that Artemis's secret weapon is a copy of the Book of the People. He fakes his death in a cave-in as a bid for freedom, and steals bars of gold from the Lower Elements Police Holly Short (the elf captured by Artemis Fowl) ransom fund before tunnelling away.

Mulch was lured by Artemis Fowl to steal the priceless Fei Fei tiara which contains an enormous blue diamond. However, a group of six dwarves led by Sergei the Significant have already stolen the tiara and plan to sell it at a circus to several European jewellery fences. As the dwarves perform in the circus, Mulch sneaks in underground and takes the tiara, also knocking out their leader, Sergei.

In Artemis Fowl and the Arctic Incident, he has used the gold he stole in the first book to buy himself a fancy apartment in Los Angeles, under the alias Lance Digger.[2] He quickly returns to his old ways, and becomes a thief known as "The Grouch", famous for stealing one of every Academy Award trophy. After being found by Artemis and Holly Short, he helps them break into Opal Koboi's laboratories, in exchange for a two-day head start, which he takes as soon as the mission is over.

In Artemis Fowl and the Eternity Code, he is initially working for the Antonelli family as a "monkey" (which means someone who is good at breaking into places) under the alias Mo Digence, but foils a plot to kidnap Artemis, and subsequently assists him in breaking into the Spiro Needle to steal back the C Cube. After this, Artemis Fowl helps him by changing the date on his original search warrant, rendering all further convictions void. Artemis gives him a gold medallion which is actually a computer disc with information to help Artemis recover his memories after the mind wipe.

In the fourth book, Artemis Fowl and the Opal Deception, he is en route to his hearings when he hears of Commander Root's death and escapes from and steals a LEPrecon shuttle, knowing that Holly couldn't have committed the murder and regarding Root as a 'sort of' friend (He is spared from Koboi's revenge as the LEP didn't advertise his involvement in her defeat to save face). He delivers the disc Artemis gave him to Butler, Artemis' bodyguard, restoring Butler's memory and allowing the two of them to come up with a plan to rescue Artemis and Holly Short from Opal Koboi, in the Eleven Wonders Exhibition in the Lower Elements which was full of trolls.[3] Mulch joins forces with Holly Short, Artemis Fowl, and Domovoi Butler. Mulch sneaks aboard Opal's vehicle and moves the shaped charges to the "booty box." He also steals all of Koboi's precious truffles along with one of her diamond earrings.

In Artemis Fowl and the Lost Colony, Mulch, now a PI (private investigator), is needed by Artemis Fowl to foil a plan to expose the missing demon race. He helps them break into the Paradizo chateau, rescue Minerva Paradizo from the clutches of Billy Kong and while Holly is away in Limbo, he runs the PI firm with another ex-criminal partner, Doodah Day.[4]

While Artemis and Holly are trapped in the past, a "younger" Mulch rescues them from Artemis' younger self. He then agrees to accompany them to save the silky sifaka lemur for a stupendous amount of gold.[5] The three friends are able to successfully capture the lemur by having Mulch tunnel underneath it and steal it away from Dr Kronksi, but Holly is kidnapped by the younger Artemis. Mulch stays with the lemur until Artemis rescues her, and they return to Fowl Manor. He is accosted by Opal Koboi who drains his memories from the past three days to find Artemis and Holly, and doesn't remember the experience, or his shoe size.

Mulch Diggums played a pivotal role in saving Artemis's life several times, ultimately ruining Opal Koboi's plan. He also displayed his ability to ride a troll.