The Trap Parents

Bob is Conveniently an Orphan, and lives a life of adventure and excitement with his friends.

Then, one day, he gains some parents—either his real parents turn up alive, or he meets somebody who would just love to adopt him. The new parents are loving and attentive and everything parents should be—but they're determined that Bob should have nothing further to do with his True Companions. All that running around having adventures may have been all right when he had no parents to teach him better, but they're here now. So Bob bids a tearful farewell to his friends, especially those he'd come to think of as parental figures, and off he goes to what everybody is firmly telling themselves will be a happy life.

Then Status Quo Is God takes a hand: Once Bob is on his own, it's not long before he discovers that the whole loving parent thing has been an act to get him in their power for some sinister purpose. Then it's up to Bob to escape (or his True Companions, who never quite trusted those two), to rescue him.

If the fake parents are not the real antagonist, but have been employed by somebody else, they may find themselves Becoming the Mask and help Bob escape.

It also counts if the audience knows that the new parents are phonies before Bob and his friends find out.

Not to be confused with The Parent Trap.

Comic Books

 * A Spider-Man story arc had Peter Parker's parents turn up alive and well, but they were actually robot duplicates created by one of Spider-Man's enemies.
 * In the Ultimate Spider-Man version of The Clone Saga,
 * In a Golden Age Batman comic, Dick Grayson's uncle and aunt appear to claim custody of Dick, which a court grants. It turns out to be a con with them willing to waive their custodial rights in exchange for a hefty bribe from Bruce Wayne.

Film

 * Stuart Little: Stuart's real parents reclaim him, but they're actually impostors and it's part of a plot to separate him from his new family.
 * An interesting subversion of this trope occurs in Secondhand Lions, in that one of The Trap Parents is Walter Coleman's actual mother.

Literature

 * In Maximum Ride, Iggy finds his real parents, and they actually are his real parents—but they don't care about him except as a cash cow, so he rejoins his True Companions anyway.
 * In Animorphs, Tobias's "cousin" appears in town hoping to adopt him. Said cousin is actually a morphed Visser Three, who found a letter written by Tobias's real father, discovered that Tobias had apparently vanished off the face of the Earth, and made the connection that Tobias may have had connections to the "Andalite bandits". Fortunately, Tobias discovers the facade before the adoption takes place.
 * The adoption was never actualy going to happen. He discovered the ruse before the reading of Elfangor's letter so he was able to suppress any emotion that would have given him away to Visser Three.
 * In Escape to Witch Mountain, a man appears at the orphanage claiming to be Tony and Tia's uncle. He's actually there to capture them and their supernatural abilities. In the Disney film, he appears after Tia saves his life.

Live-Action TV

 * The Sarah Jane Adventures, "The Lost Boy": Sarah Jane's adopted son Luke is reclaimed by his "real parents", who are actually disguised aliens who need him for their evil plan.
 * The live-action Superboy series, "Abandon Earth": Superboy's parents show up alive to take him home to Krypton, but they're actually shape-shifting aliens.
 * Star Trek: Voyager, "Child's Play": Former Borg Kid, Icheb, is returned to his actual birth parents. Then, it turns out they bioengineered him as a genetic superweapon to destroy the Borg and send him to die. Again. Voyager saves him.
 * The live action version of The Tick (animation) managed to do this with Tick's alleged wife rather than parents. In that case, The Tick was such an extreme Cloudcuckoolander that he somehow didn't know who he even was (legally speaking, anyway). When a woman showed up out of nowhere with documents to prove he was her amnesiac husband, he went with it, leaving his True Companions feeling oddly betrayed. The Tick gets frustrated when the fake wife demands he give up crime fighting and lead a normal life; the documents turned out to be forged and the wife Ax Crazy, necessitating a rescue.
 * In Just Shoot Me, a couple claims to be Nina's real parents. Maya later learns that they are con artists and warns Nina through the elevator intercom. Nina doesn't believe it until she sees them attempting an Elevator Escape.

Theater

 * Annie: After Warbucks offers a reward for information about Annie's family, her real parents show up to claim her, but they're actually just con artists after the reward.
 * Notable in that after Daddy Warbucks offers the reward, hundreds of people showed up claiming to be Annie's parents, meaning they were all trying for this Trope. It's just one of the two con artists in question was the brother of Miss Hannigan, who ran the orphanage Annie lived at and could provide them with confidential info about how to pull off the job.

Western Animation

 * Adventures of Sonic the Hedgehog: Tails is adopted by a loving fox family who later turn out to be robots created by Dr. Robotnik to capture him. Sonic figured out something was wrong when he realised they called him Tails, the nickname Sonic gave him, instead of his real name, "Miles".
 * Xiaolin Showdown - Omi, the only member of the team without a family. At the end of the episode, his friends remind him that he does have one.
 * Teamo Supremo, "The Parents From Another Planet!": Captain Crandall's "real alien parents" show up, but they're actually con artists.