The Lord of the Rings novels and film adaptations are full of beloved characters, but even amongst this illustrious company, Peregrin "Pippin" Took stands out as a fan favorite. The youngest of the Fellowship's four Hobbit members, Pippin is cheerful, curious and prone to getting into mischief. His hilariously naïve and carefree personality brings much-needed humor to an often dark tale, and his close friendship with his cousin Meriadoc "Merry" Brandybuck is truly heartwarming.
Pippin's faults are nearly as numerous as his charms, though, and his propensity for doing the wrong thing at the wrong time gets himself and his companions into fairly serious trouble several times over the course of The Lord of the Rings. In fact, he makes outrageously bad mistakes so often that it's almost a little... suspicious. Though it feels sacrilegious to even consider it, what if Pippin's clumsiness and scatterbrained behavior is actually all an act? Could the sweet and silly Hobbit actually be a secret agent of Sauron?
As ludicrous as this theory sounds, there is actually some interesting evidence for it -- especially when one notices just how many opportunities Pippin has to do some serious damage and information-gathering for the Dark Lord. As Frodo's distant cousin and friend, Pippin is present at Bilbo's birthday celebration and witnesses the elder Baggins' disappearing act. In the novels, he is one of the "Conspirators" (along with Merry, Sam and Fatty Bolger) aware of the Ring's existence and Frodo's intentions to leave the Shire. They spy on him to ensure he doesn't sneak off on his own, and Merry even peeks at Bilbo's diary, sharing his findings with Pippin and others.
In Peter Jackson's The Fellowship of the Ring adaptation, Pippin loudly tells the other guests at the Prancing Pony in Bree about the events of Bilbo's party years before -- an extremely reckless thing to do, given that the Ringbearer is actively being hunted by the minions of Mordor. This careless move forces Frodo to create a distraction, which results in him donning the Ring and drawing the Nazgûl straight to the inn. Later, at Rivendell, Pippin (along with Merry) insists on insinuating himself into the Fellowship, despite acting like he doesn't even understand the mission at hand.
At the mines of Moria, Pippin's mischief reaches new heights. First (though this is only in the film), he throws stones at the Watcher in the Water, likely causing it to wake and forcing the Fellowship to flee inside, away from the monster's tentacles. He then proceeds, infamously, to drop a stone down a well. This misstep is even worse in the film adaptation as it's a helmet, followed by an entire skeleton that awakens "the drums in the deep," aka a seemingly endless wave of orcs and cave-trolls. This commotion may have also provoked the Balrog, leading to Gandalf's "death" and one of the Fellowship's darkest moments.
The incident at Moria is rivaled only by Pippin's later misadventure with the palantír of Isengard, which he develops an instant and unshakeable obsession with as soon as he lays eyes on it. Ignoring everyone's warnings, he steals it from a sleeping Gandalf and peers into it, allowing Sauron to perceive him and gaze into his mind. It's an important moment, depicted as the Dark Lord believing Pippin is the Hobbit who holds the Ring rather than Frodo. But what if this seemingly irrational behavior is actually Pippin finding a way to get word to his master? Gandalf subsequently takes Pippin to Minas Tirith for safekeeping. Coincidentally, that also moves him closer to Mordor, the seat of Sauron's power.
The question is, when in the narrative might Pippin have become corrupted by Sauron? Peter Jackson's The Fellowship of the Ring significantly condenses the timeline, but there's actually a 17-year gap between Bilbo's farewell party and Frodo's journey from the Shire. That provides plenty of time for Sauron's agents to hear Pippin boasting of Bilbo's sudden and mysterious disappearance. There is a possibility that the Nazgûl may have met with him in secret after arriving in the Shire prior to their first depicted encounter with the young Hobbits.
Naturally, this is a farfetched headcanon, more along the lines of crackpot thought exercises like the infamous Darth Jar Jar theory. For each of Pippin's mistakes, he also has plenty of redeeming moments where his courage and true heart shine through -- and many of his missteps actually lead to important plot developments that ultimately make The Lord of the Rings' happy moments possible, such as Gandalf's return as Gandalf the White. By the end of the tale, Pippin's matured significantly and become a valiant warrior in his own right. He even holds the distinction of being the first Hobbit to ever slay a fearsome Olog-hai troll, a feat he pulls off during the Battle of the Black Gate (though he spends the rest of the battle trapped under its dead bulk). He later achieves the position of Thain of the Shire, indicating he eventually grows into a strong and worthy leader.