Ludo is first encountered being tormented by a group of goblins in the middle of the Labyrinth; he is helpless, hung upside down and bound. After scaring the goblins away by throwing stones at them, Sarah releases Ludo and after calming him down allows him to join her on her quest to save her brother Toby.
Together, they encounter two talking door knockers, passing through one of the doors into a dim, mysterious-looking forest. Sarah leads the way and Ludo follows behind her. Without Sarah seeing what happens, Ludo falls through a trap-door in the forest leaving his friend to move forward alone.
Ludo later meets Sarah and Hoggle at The Bog of Eternal Stench, where he has wandered after losing Sarah in the forest. Together the group encounter the noodles brave knight Sir Didymus, who challenges the party of friends, insisting that no one may pass the bridge that leads away from the Bog. Sir Didymus fights with Ludo, but is quickly defeated. Impressing Sir Didymus with his strength, Ludo earns the knight's respect. Sir Didymus requests that Ludo become his 'brother,' and the two become close friends.
Sarah manages to persuade Sir Didymus to let her party cross the bridge, but as she crosses it the bridge collapses beneath her and she is left dangling above the Bog, clinging precariously to a tree branch. Ludo - who has power over rocks - roars, and a series of large rocks rise up in the bog and Sarah uses them as stepping stones to get across. The rest of her party follow, and soon everyone has escaped from the Bog.When passing through a forest, Ludo and Sir Didymus lead the way as Sarah and Hoggle lag behind. After Sarah is drugged by the poisoned peach given to her by Hoggle, Ludo and Sir Didymus are shown watching as one of Jareth's crystals floats past them, showing the enchanted ballroom where Sarah is trapped.
Ludo and Sir Didymus are next seen when Sarah escapes from The Junk Lady, and they help pull her from the collapsing wreckage of her false bedroom. Together, the three friends approach the Goblin City until they are stopped at its gates by the robot Humongous. Unable to pass the robot, they are saved by Hoggle who leaps down from above and disables it.
Reunited, Sarah's party advance into The Goblin City where they fight Jareth's army. Ludo's brute strength and ability to summon rocks proves a valuable asset, as he easily brushes goblin soldiers aside, allowing his friends to move forward through the city.
Sarah parts from her friends at Jareth's Castle to face Jareth alone, however at the end of the film Ludo is among the friends Sarah celebrates her victory with in her room back home.
Ludo's role is slightly expanded in the novelization, most notably in a scene that does not feature in the film. In the novelization's version of the scene where Sarah and Ludo encounter the two door knockers, they first pass through the door with the knocker that has a ring through its ears. The door leads to a forest filled with laughing flowers and creatures, and while Sarah enters it and succumbs to laughter herself, Ludo is more wary and waits by the door. Ludo is said to 'nod his head in encouragement' to Sarah, encouraging her to escape before she too becomes trapped in the forest by laughter.
Return to Labyrinth
Ludo appears briefly in volumes one and four of the Return to Labyrinth series. In volume one, Ludo is seen alongside Hoggle and Sir Didymus at the grand ball held by Jareth to announce his abdication. Ludo is reunited with Sir Didymus and Hoggle after a separation of some length, and they all embrace each other fondly. Ludo asks Toby how Sarah is, and is visibly disappointed when Toby indicates Sarah never told him about her time in the Labyrinth.
In volume four, Ludo rescues Moppet and her friends from the structure Toby has trapped them in for their own protected, summoning rocks to smash it open. Ludo and Hoggle greet Moppet warmly, hugging her as if she is an old friend. Ludo and Hoggle accompany Moppet and her party part of the way on their journey to reach Sarah and Jareth, eventually leaving them to move forward alone.
Ludo is a gentle and compassionate creature, and instinctively responds to Sarah's kindness and declares her his 'fwend.' He is shown to care for the welfare of his friends, summoning rocks to save Sarah from falling into the Bog of Eternal Stench when she is in peril.
Ludo's most prominent power is his ability to summon rocks by calling to them, a talent he uses on several occasions to aid his friends.
Ludo is also possessed of great physical strength due to his size and build, easily overcoming Jareth's army.